Note: Descriptions are shown in the official language in which they were submitted.
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COLLAGEN 7 PROTEIN REPLACEMENT THERAPY
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to recombinant collagen 7
protein therapy for
Dystrophic Epidermolysis Bullosa (DEB), in particular Recessive Dystrophic
Epidermolysis
Bullosa (RDEB).
REFERENCE TO THE SEQUENCE LISTING
[0002] The present application is being filed along with a Sequence
Listing in electronic
format. The Sequence Listing is provided as a file entitled 51624-
014W03 Sequence Listing 10_7 22.xml, created on October 7. 2022, which is
14,778
bytes in size. The information in the electronic format of the sequence
listing is incorporated
herein by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
[0003] Epidermolysis bullosa (EB) encompasses a group of
molecularly diverse diseases
characterized by the development of blisters after minor mechanical trauma to
the skin.
Almost all patients experience severe, recurrent blistering or ruptured skin,
although severity,
extracutaneous manifestations, and clinical course depend on the type of EB.
The four major
types of inherited EB include EB simplex, junctional EB, dystrophic EB (DEB),
and Kindler
syndrome and are differentiated based on the level of the skin and/or
noncutaneous tissue
where the absent or affected protein is located and where the blisters and
their clinical
manifestations develop.
[0004] DEB, one of the most severe forms of EB, is characterized by recurrent
blistering
with subsequent healing and scarring. In patients with DEB, blistering can be
triggered by
even minor mechanical trauma owing to the extremely fragile nature of the
skin. This leads to
a chronic cycle of blistering, healing, and re-blistering that causes patients
to suffer from
painful wounds and debilitating scarring of epithelial tissue.
[0005] DEB is caused by mutations in the COL7A1 gene, which encodes the alpha
chain of
type VII collagen (Co17), a protein essential for the formation of the fibrils
that anchor the
basement membrane to the underlying dermis. The condition is inherited as
either a dominant
(DDEB) or a recessive form (RDEB). The recessive form typically presents with
a more
severe phenotype and in the most severe generalized form of RDEB, wounds
affecting the
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whole body may be present. The correlation between genotype and phenotype of
RDEB and
COL7A1 mutations is highly variable.
[0006] The extent of cutaneous involvement ranges from localized blistering of
the
extremities to widespread lesions. It is common for patients with all forms of
DEB to have
dystrophy or loss of nails. Scarring of the hands and feet causing webbing
between the digits
known as pseudosyndactyly, with progression to mutilating deformities in which
the fingers
or toes are encased in scar tissue, is most characteristic of severe,
generalized RDEB, while
pseudo syndactyly is infrequent in DDEB.
[0007] The behavior of wounds in DEB, particularly in more severe forms of the
disease
RDEB, has several distinct characteristics. The wounds are dynamic and occur
due to the
skin's impaired mechanical resistance to external shear forces; they heal but
may recur,
reflecting continued risk for mechanical injury that led to the first wound as
well as
alterations in the healing process due to Col7 deficiency. Characteristic
features of DEB
include life-long skin fragility and healing with scarring, apparently due to
effects on two
interconnected Co17-dependent mechanisms.
[0008] In addition to the cutaneous symptoms, severe forms of DEB can cause
erosion and
scarring of mucous membranes such as those of the eye, mouth and esophagus,
genitals, and
anus; dental abnormalities are also common. Oral involvement may lead to mouth
blistering,
fusion of the tongue to the floor of the mouth, and progressive diminution of
the size of the
oral cavity. Esophageal erosions can lead to webs and strictures that can
cause severe
dysphagia. Consequently, nutritional deficiency, anemia, and other secondary
problems are
common. Corneal erosions can lead to scarring and loss of vision. Blistering
of the hands and
feet followed by scarring results in pscudosyndactyly, a hallmark of this
disorder. The
lifetime risk of aggressive squamous cell carcinoma is higher than 90%. Other
forms of DEB
have similar, but less pronounced clinical findings.
[0009] Pathogenic mutations in the COL7A1 gene lead to abnormal, decreased or
a
complete absence of anchoring fibrils in the skin, resulting in DEB. This lack
of normal
functioning anchoring fibrils is responsible for poor epidermal-dermal
adherence, pronounced
skin fragility and severe blistering in the skin and mucosa in DEB patients.
[0010] There is no definitive treatment for DEB and its management focuses on
supportive
care. Bandaging and infection prevention are the main strategies for
management of all forms
of EB, alone with pain and itch relief, nutritional support, and surgical
management as
required. Current standard of care with allografts is of very limited benefit
in RDEB patients,
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as 0% of wounds in RDEB were reported healed after 16 weeks of grafting
because of the
chronic and dynamic nature of wounds in RDEB patients. There is, however, no
uniformly
accepted standard of care: the choice of bandages, routine, and distraction
techniques differs
among families and centers. Severely affected patients with wide-ranging
cutaneous and
extracutaneous symptoms also require a multidisciplinary approach to
treatment. Patients
with DEB experience diminished health-related quality of life (HRQL) due to
pain, pruritus,
decreased activities of daily living, fatigue, reduced weight, and the social
impact of disease
manifestations.
[0011] DEB is a devastating systemic disease with no effective therapy. No
systemic
disease modifying approaches are known to be in development. Because DEB' s
debilitating
effects arise from deficiencies in functional Col7, DEB is appropriate for
systemic protein
therapy with recombinant human Col7 (rhCo17). The present disclosure provides
rCol7 (e.g.,
rhCo17) protein therapies for systemically treating DEB.
SUMMARY OF THE DISCLOSURE
[0012] The present disclosure relates to collagen 7 (alternately referred to
herein as co17,
Col7, or C7), specifically recombinant human collagen 7 (alternately referred
to herein as
rhCol7 or rhC7) protein replacement therapy for treatment of dystrophic
epidermolysis
bullosa (DEB), especially recessive DEB (RDEB). The treatment relates to
systemic
administration of a recombinant collagen 7 (e.g., rCol7, such as rhCo17)
substance to subjects
with DEB by intravenous administration, e.g., intravenous infusion. The
present disclosure is
based in part on the premise that rCol7 protein is able to deposit within
wounded and
unwounded skin sites, specifically concentrating at the dermal-epidermal
junction (DEJ),
through systemic administration, and thus can be used to treat, prevent, delay
the onset of,
ameliorate a complication and/or symptom of, and/or prevent the progression of
a clinical
complication and/or symptom associated with DEB.
[0013] In an aspect, the present disclosure provides a method of treating
dystrophic
epidermolysis bullosa (DEB) in a subject in need thereof, comprising
intravenously
administering to the subject a recombinant human Col7 (rhCo17) substance
according to a
first dosing regimen and a second dosing regimen, wherein: i) the first dosing
regimen
includes administering a first therapeutically effective amount of the
substance at a first
frequency; and ii) the second dosing regimen includes administering a second
therapeutically
effective amount of the substance at a second frequency, wherein the first
frequency is
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greater than the second frequency, and wherein administration according to the
first dosing
regimen occurs prior to administration according to the second dosing regimen.
[0014] In another aspect, the present disclosure provides a method of
ameliorating,
alleviating, reducing, improving, delaying onset of, delaying progression of,
eliminating,
and/or curing a symptom or complication of dystrophic epidermolysis bullosa
(DEB) in a
subject in need thereof, comprising intravenously administering to the subject
a recombinant
human Col7 (rhCo17) substance according to a first dosing regimen and a second
dosing
regimen, wherein: i) the first dosing regimen includes administering a first
therapeutically
effective amount of the substance at a first frequency; and ii) the second
dosing regimen
includes administering a second therapeutically effective amount of the
substance at a second
frequency, wherein the first frequency is greater than the second frequency,
and wherein
administration according to the first dosing regimen occurs prior to
administration according
to the second dosing regimen.
[0015] In a further aspect, the present disclosure provides a Col7 substance
(e.g., a
recombinant human Col7, rhCo17) for use in a method of treating dystrophic
epidermolysis
bullosa (DEB) in a subject in need thereof, the method comprising
administering to the
subject a recombinant human Col7 (rhCo17) substance according to a first
dosing regimen
and a second dosing regimen, wherein: i) the first dosing regimen includes
administering a
first therapeutically effective amount of the substance at a first frequency;
and ii) the second
dosing regimen includes administering a second therapeutically effective
amount of the
substance at a second frequency, wherein the first frequency is greater than
the second
frequency, and wherein administration according to the first dosing regimen
occurs prior to
administration according to the second dosing regimen.
[0016] In a related aspect, the present disclosure provides a Col7 substance
(e.2., a
recombinant human Col7, rhCo17) for use in a method of ameliorating,
alleviating, reducing,
improving, delaying onset of, delaying progression of, eliminating, and/or
curing a symptom
or complication of dystrophic epidermolysis bullosa (DEB) in a subject in need
thereof, the
method comprising intravenously administering to the subject a recombinant
human Col7
(rhCo17) substance according to a first dosing regimen and a second dosing
regimen,
wherein: i) the first dosing regimen includes administering a first
therapeutically effective
amount of the substance at a first frequency; and ii) the second dosing
regimen includes
administering a second therapeutically effective amount of the substance at a
second
frequency, wherein the first frequency is greater than the second frequency,
and wherein
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administration according to the first dosing regimen occurs prior to
administration according
to the second dosing regimen.
[0017] In a related aspect, the present disclosure provides a use of a Col7
substance (e.g., a
recombinant human Co17, rhCo17) for the manufacture of a medicament for the
treatment of
dystrophic epidermolysis bullosa (DEB) or a symptom or complication thereof,
wherein the
treatment comprises administering to a subject in need thereof a recombinant
human Col7
(rhCo17) substance according to a first dosing regimen and a second dosing
regimen,
wherein: i) the first dosing regimen includes administering a first
therapeutically effective
amount of the substance at a first frequency; and ii) the second dosing
regimen includes
administering a second therapeutically effective amount of the substance at a
second
frequency, wherein the first frequency is greater than the second frequency,
and wherein
administration according to the first dosing regimen occurs prior to
administration according
to the second dosing regimen.
[0018] In a related aspect, the present disclosure provides a use of a Col7
substance (e.g., a
recombinant human Col7, rhCo17) for the manufacture of a medicament for the
amelioration,
alleviation, reduction, improvement, delay of onset of, delay of progression
of, elimination,
and/or curing of a symptom or complication of dystrophic epidermolysis bullosa
(DEB),
wherein the amelioration, alleviation, reduction, improvement, delay of onset
of, delay of
progression of, elimination, and/or curing comprises administering to a
subject in need
thereof a recombinant human Col7 (rhCo17) substance according to a first
dosing regimen
and a second dosing regimen, wherein: i) the first dosing regimen includes
administering a
first therapeutically effective amount of the substance at a first frequency;
and ii) the second
dosing regimen includes administering a second therapeutically effective
amount of the
substance at a second frequency, wherein the first frequency is greater than
the second
frequency, and wherein administration according to the first dosing regimen
occurs prior to
administration according to the second dosing regimen.
[0019] In some embodiments of the preceding aspects, the symptom or
complication of
DEB is skin wounds including blistering, itching, pain, skin erosion,
scarring, skin fragility,
gangrene, aplasia or hypoplasia of the skin, hypopigmentation of skin, milia,
skin infections,
cheilitis (e.g., inflammation of lips), dystrophic fingernails or toenails,
abnormal dental
enamel, pseudosyndactyly or camptodactyly of fingers or toes, finger or toe
syndactyly,
flexion contracture of toes, carious teeth, dysphagia (e.g., poor swallowing),
furrowed or
grooved tongue, esophageal stricture, laryngeal stenosis, failure to thrive,
dilated
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cardionayopathy, abnormal pulmonary interstitial morphology, acute
constipation, hearing or
visual impairment, eczema, glomerulopathy, immunologic hypersensitivity,
nasolacrimal
duct obstruction, anemia, chronic ear infections, corneal erosion, corneal
abrasions and
scarring, micro stomia, osteopenia, ectropion, immunologic hypersensitivity,
nephrotic
syndrome, phimosis, renal insufficiency, urinary retention, ureteral stenosis,
stroke,
squamous cell carcinoma, or a combination thereof. In some embodiments, the
symptom or
complication of DEB is skin wounds including blistering, skin erosion,
scarring, skin
fragility, aplasia or hypoplasia of the skin, cheilitis (e.g., inflammation of
lips), dystrophic
fingernails or toenails, pseudosyndactyly or camptodactyly of fingers or toes,
finger or toe
syndactyly, flexion contracture of toes, dysphagia (e.g., poor swallowing),
esophageal
stricture, laryngeal stenosis, or a combination thereof. In some embodiments,
the symptom
or complication of DEB is skin wounds including blistering.
[0020] In some embodiments of the preceding aspects, the method ameliorates,
alleviates,
reduces, improves, or eliminates one or more skin wounds.
[0021] In some embodiments of the preceding aspects, the first dosing regimen
lasts at least
one week. In some embodiments, the first dosing regimen lasts at least two
weeks. In some
embodiments, the first dosing regimen lasts at least three weeks. In some
embodiments, the
first dosing regimen lasts at least four weeks. In some embodiments, the first
frequency is
about daily, about every two days, about every three days, about every four
days, about every
five days, about every six days, about every week, about every ten days, or
about every two
weeks. In some embodiments, the first frequency is weekly.
[0022] In some embodiments of the preceding aspects, the second dosing regimen
lasts at
least four weeks. In some embodiments, the second dosing regimen lasts at
least six weeks.
In some embodiments, the second dosing regimen lasts at least seven weeks. In
some
embodiments, the second dosing regimen lasts at least eight weeks. In some
embodiments,
the second dosing regimen lasts at least six months. In some embodiments, the
second
dosing regimen lasts at least one year. In some embodiments, the second dosing
regimen
comprises administering the rhCol7 substance to the subject over the subject's
lifetime. In
some embodiments, the second frequency is about every week, about every ten
days, about
every two weeks, about every three weeks, about every four weeks, or about
every month. In
some embodiments, the second frequency is weekly. In some embodiments, the
second
frequency is every other week. In some embodiments, the second dosing regimen
is chronic
(e.g., lasts the subject's lifetime).
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[0023] In some embodiments of the preceding aspects, the first dosing regimen
lasts
between one week and four weeks, and the second dosing regimen lasts at least
six weeks. In
some embodiments, the first dosing regimen lasts one week. In some
embodiments, the first
dosing regimen lasts two weeks. In some embodiments, the first dosing regimen
lasts three
weeks. In some embodiments, the first dosing regimen lasts four weeks. In some
embodiments, the second dosing regimen lasts seven weeks. In some embodiments,
the
second dosing regimen lasts at least six months. In some embodiments, the
second dosing
regimen comprises administering the rhCol7 substance to the subject over the
subject's
lifetime. In some embodiments, the first dosing regimen lasts four weeks, and
the second
dosing regimen lasts at least seven weeks.
[0024] In some embodiments of the preceding aspects, the first effective
amount is about
0.01 mg/kg, 0.05 mg/kg, 0.1 mg/kg, 0.2 mg/kg, 0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg,
0.6 mg/kg,
0.7mg/kg, 0.8 mg/kg, 0.9 mg/kg, 1.0 mg/kg, 1.1 mg/kg 1.2 mg/kg, 1.3 mg/kg, 1.4
mg/kg,
1.5mg/kg, 1.6 mg/kg, 1.7 mg/kg, 1.8 mg/kg, 1.9 mg/kg, 2.0 mg/kg, 2.1 mg/kg,
2.2 mg/kg, 2.3
mg/kg, 2.4 mg/kg, 2.5 mg/kg, 2.6 mg/kg, 2.7 mg/kg, 2.8 mg/kg, 2.9 mg/kg, 3.0
mg/kg, 3.1
mg/kg, 3.2 mg/kg, 3.3 mg/kg, 3.4 mg/kg, 3.5 mg/kg, 3.6 mg/kg, 3.7 mg/kg, 3.8
mg/kg, 3.9
mg/kg, 4.0 mg/kg, 4.5 mg/kg, 5.0 mg/kg, 6.0 mg/kg, 7.0 mg/kg, 8.0 mg/kg, 9.0
mg/kg, 10
mg/kg, 15 mg/kg, or 20 mg/kg. In some embodiments, the first effective amount
is about 0.1
mg/kg, 0.3 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5mg/kg, 2.0 mg/kg, or 3.0 mg/kg. In
some
embodiments, the second effective amount is about 0.1 mg/kg. In some
embodiments, the
first effective amount is about 0.3 mg/kg. In some embodiments, the second
effective
amount is about 0.5 mg/kg. In some embodiments, the second effective amount is
about 1.0
mg/kg. In some embodiments, the second effective amount is about 1.5 mg/kg. In
some
embodiments, the second effective amount is about 2.0 mg/kg. In some
embodiments, the
first effective amount is about 3.0 mg/kg.
[0025] In some embodiments of the preceding aspects, the second effective
amount is about
0.01 mg/kg, 0.05 mg/kg, 0.1 mg/kg, 0.2 mg/kg, 0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg,
0.6 mg/kg,
0.7mg/kg, 0.8 mg/kg, 0.9 mg/kg, 1.0 mg/kg, 1.1 mg/kg 1.2 mg/kg, 1.3 mg/kg, 1.4
mg/kg,
1.5mg/kg, 1.6 mg/kg, 1.7 mg/kg, 1.8 mg/kg, 1.9 mg/kg, 2.0 mg/kg, 2.1 mg/kg,
2.2 mg/kg, 2.3
mg/kg, 2.4 mg/kg, 2.5 mg/kg, 2.6 mg/kg, 2.7 mg/kg, 2.8 mg/kg, 2.9 mg/kg, 3.0
mg/kg, 3.1
mg/kg, 3.2 mg/kg, 3.3 mg/kg, 3.4 mg/kg, 3.5 mg/kg, 3.6 mg/kg, 3.7 mg/kg, 3.8
mg/kg, 3.9
mg/kg, 4.0 mg/kg, 4.5 mg/kg, 5.0 mg/kg, 6.0 mg/kg, 7.0 mg/kg, 8.0 mg/kg, 9.0
mg/kg, 10
mg/kg, 15 mg/kg, or 20 mg/kg. In some embodiments, the second effective amount
is about
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0.1 mg/kg, 0.3 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5mg/kg, 2.0 mg/kg, or 3.0 mg/kg.
In some
embodiments, the second effective amount is about 0.1 mg/kg. In some
embodiments, the
second effective amount is about 0.3 mg/kg. In some embodiments, the second
effective
amount is about 0.5 mg/kg. In some embodiments, the second effective amount is
about 1.0
mg/kg. In some embodiments, the second effective amount is about 1.5 mg/kg. In
some
embodiments, the second effective amount is about 2.0 mg/kg. In some
embodiments, the
second effective amount is about 3.0 mg/kg.
[0026] In some embodiments of the preceding aspects, the first effective
amount is the
same as the second effective amount. In some embodiments, the first effective
amount and
the second effective amount are independently about 0.01 mg/kg, 0.05 mg/kg,
0.1 mg/kg, 0.2
mg/kg, 0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg, 0.6 mg/kg, 0.7mg/kg, 0.8 mg/kg, 0.9
mg/kg, 1.0
mg/kg, 1.1 mg/kg 1.2 mg/kg, 1.3 mg/kg, 1.4 mg/kg, 1.5mg/kg, 1.6 mg/kg, 1.7
mg/kg, 1.8
mg/kg, 1.9 mg/kg, 2.0 mg/kg, 2.1 mg/kg, 2.2 mg/kg, 2.3 mg/kg, 2.4 mg/kg, 2.5
mg/kg, 2.6
mg/kg, 2.7 mg/kg, 2.8 mg/kg, 2.9 mg/kg, 3.0 mg/kg, 3.1 mg/kg, 3.2 mg/kg, 3.3
mg/kg, 3.4
mg/kg, 3.5 mg/kg, 3.6 mg/kg, 3.7 mg/kg, 3.8 mg/kg, 3.9 mg/kg, 4.0 mg/kg, 4.5
mg/kg, 5.0
mg/kg, 6.0 mg/kg, 7.0 mg/kg, 8.0 mg/kg, 9.0 mg/kg, 10 mg/k2, 15 mg/kg, or 20
mg/kg. In
some embodiments, the first effective amount and the second effective amount
are
independently about 0.1 mg/kg, 0.3 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5mg/kg, 2.0
mg/kg, or
3.0 mg/kg. In some embodiments, the first effective amount and the second
effective amount
are each about 0.3 mg/kg. In some embodiments, the first effective amount and
the second
effective amount are each about 3.0 mg/kg.
[0027] In some embodiments of the preceding aspects, the first dosing regimen
lasts at least
one week, the first frequency is weekly, and the first effective amount is
about 0.1 mg/kg, 0.3
mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5mg/kg, 2.0 mg/kg, or 3.0 mg/kg. In some
embodiments, the
first dosing regimen lasts four weeks. In some embodiments, the first
effective amount is
about 0.3 mg/kg. In some embodiments, the first effective amount is about 3.0
mg/kg. In
some embodiments, the second dosing regimen lasts at least four weeks, the
second
frequency is every other week, and the second effective amount is about 0.1
mg/kg, 0.3
mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5mg/kg, 2.0 mg/kg, or 3.0 mg/kg. In some
embodiments, the
second dosing regimen lasts at least seven weeks. In some embodiments, the
second dosing
regimen is chronic. In some embodiments, the second dosing regimen lasts over
the patient's
lifetime. In some embodiments, the second effective amount is about 0.3 mg/kg.
In some
embodiments, the second effective amount is about 3.0 mg/kg.
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[0028] In some embodiments of the preceding aspects, the intravenous
administration is by
intravenous infusion, or slow push injection.
[0029] In some embodiments of the preceding aspects, the subject has recessive
dystrophic
epidermolysis bullosa (RDEB).
[0030] In some embodiments of the preceding aspects, the subject has dominant
dystrophic
epidermolysis bullosa (DDEB).
[0031] In some embodiments of the preceding aspects, the subject has a
mutation in the
COL7A1 gene that is consistent with a recessive inheritance pattern.
[0032] In some embodiments of the preceding aspects, the subject is a human.
In some
embodiments, the subject is under 18 years of age. In some embodiments, the
subject is at
least 6 years of age. In some embodiments, the subject is at least 2 years of
age. In some
embodiments, the subject is less than 2 years of age. In some embodiments, the
subject is at
least 18 years of age.
[0033] In some embodiments of the preceding aspects, the rhCol7 substance is
included in
a pharmaceutical composition comprising 1.2 mg/mL rhCo17 substance, 10 mM
sodium
phosphate, 5 mM sodium citrate, 100 mM L-arginine, 1.7% sucrose (w/v), 70 mM
sodium
chloride, and 0.05% (v/v) polysorbate 20 (pH 7.2).
[0034] In some embodiments of the preceding aspects, the second dosing regimen
duration,
second frequency, and/or second effective amount is determined at least in
part based on an
assessment of one or more clinical parameters of the subject performed during
or after the
first dosing regimen. In some embodiments, the method further comprises,
between the first
dosing regimen and the second dosing regimen, assessing one or more clinical
parameters. In
some embodiments, the method further comprises, during the first dosing
regimen, assessing
one or more clinical parameters. In some embodiments, the method further
comprises, during
the second dosing regimen, assessing one or more clinical parameters. In some
embodiments, the one or more clinical parameters are selected from wound
surface area,
wound healing, time to chronic wound healing, and time in re-blistering.
BRIEF SUMMARY OF THE DRAWINGS
[0035] FIG. 1 shows representative images of dose dependent deposition of Co17
in tongue
and skin in Col7a1-/- mice following three intravenous injections.
[0036] FIG. 2A shows representative images (Hematoxylin & Eosin staining) of
tongue
tissues in Col7a1-/- mice following a single intravenous administration of
rhCo17.
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[0037] FIG. 2B is a histogram of the portion of Col7a1-/- mice with closure of
dermal-
epidermal separation in tongue following as single administration of Co17.
[0038] FIG. 3 shows the PTR-01 exposure-dependent deposition of Co17. All the
patients
received rCol7 replacement achieved increases in Col7 at or above 35% normal
human skin
(NHS). Ph2 patients (black data points) received 4x 3mg/kg weekly (1 ¨ 29
days), plus 7x
3mg/kg every other week (42 ¨ 120 days) vs. Phi patients received only 3x PTR-
01 doses bi-
weekly (1 ¨ 29 days). *Day 22 and 120 unwounded samples for 202-001 were poor
quality,
no data¨data shown is for wounded sample. Patients 02-06, 02-07, 02-08
participated in the
Phase 1/2 study. NHS: normal human skin.
[0039] FIG. 4 schematically illustrates the study design for a Phase 2, Open
Label study of
PTR-01. qow: every other week.
[0040] FIG. 5 shows the comparison of Day 120 wound evaluations vs. baseline.
[0041] FIG. 6 shows the wound response by percent reduction in wound surface
area by
Canfield imaging. * N wound images were not available for Day 36 (wound 6;
patient 201-
001) and Day 92 (wound 1; patient 201-002); therefore, wound surface areas for
these
patients at those time points were omitted. Numbers in the shaded bars
represent the number
of wounds in each percentage category; the number above each bar is the total
number of
wounds assessed at that timepoint.
[0042] FIG. 7 shows the wound closure observed in chronic and recurrent
wounds.
[0043] FIG. 8 shows example wound images demonstrating clear reduction in
wound
surface area post PTR-01 treatment.
[0044] FIGs. 9A-9B show individual wound and median change from baseline in
wound
surface area. AUC: area under the curve (cumulative wound surface area from
baseline);
N/A: not applicable; * Hodges-Lehmann estimate of difference in medians = -
18.01, 95% Cl
= (-40.35,7.19); Wilcoxon rank-sum p = 0.1776.
[0045] FIGs. 10A-10B show improvements in pain, disease impact, activities of
daily
living, mood, and essential functions measured by iscorEB-P by patients in the
Phase 2 study.
iscorEB-P: Patient reported assessment of iscorEB instrument.
[0046] FIG. 11 shows Investigator and Patient Global Impression of Change
(CAC) score
by patient and time point. * Data point missing. Patient 203-001 is not shown.
The number
above each column is the number of patients with that score and the height of
the column
reflects the IGIC or PGIC score. Note that the only decline in perceived
global status
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occurred in patient 203-002 at 3 months after the end of treatment. IGI:
Investigator Global
Impression; PGI: Patient Global Impression.
[0047] FIG. 12 shows reduction in skin pro-fibrotic biomarker staining with
PTR-01
administration. 'Scoring was performed on a 3-point scale (1=10w; 2=moderate;
3=high). N
= 5 patients (study completers).
DETAILED DESCRIPTION OF THE DISCLOSURE
[0048] The present disclosure provides methods of treating a skin disorder
(e.g., dystrophic
epidermolysis bullosa (DEB), such as recessive DEB), and/or ameliorating,
alleviating,
reducing, improving, delaying onset of, delaying progression of, eliminating,
and/or curing a
symptom or complication of a skin disorder such as DEB in a subject (e.g., a
human subject)
in need thereof. The methods provided herein may involve administering a
pharmaceutical
composition comprising a collagen 7 (e.g., C7, co17, or Co17, such as a
recombinant collagen
7 (rCo17), such as a recombinant human collagen 7 (rhCo17)), or a functional
variant thereof,
to the subject according to a first dosing regimen and a second dosing
regimen. The first
dosing regimen may be a "loading" dosing phase in which a subject is provided
a higher dose
of collagen 7 and/or is administered collagen 7 at a higher frequency than in
the second
dosing regimen. The second dosing regimen may be a "maintenance" dosing phase
in which
the subject is provided a lower dose of collagen 7 and/or is administered the
collagen 7 at a
lower frequency than in the first dosing regimen. The use of distinct dosing
regimens may
serve to acclimate the subject to the therapy and address acute symptoms
during the loading
phase, and to maintain the therapeutic benefits of the collagen 7 therapy and
prevent the
development or worsening of symptoms during the maintenance phase. The loading
phase
may last for one or more days, weeks, or months, while the maintenance phase
will generally
be longer than the loading phase and may last for weeks, months, or years, and
may extend
through the subject's lifetime.
[0049] The details of one or more embodiments of the disclosure are set forth
in the
accompanying description below. Although any materials and methods similar or
equivalent
to those described herein can be used in the practice or testing of the
present disclosure, the
preferred materials and methods are now described. Other features, objects and
advantages of
the disclosure will be apparent from the description. In the description, the
singular forms
also include the plural unless the context clearly dictates otherwise. Unless
defined otherwise,
all technical and scientific terms used herein have the same meaning as
commonly
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understood by one of ordinary skill in the art to which this disclosure
belongs. In the case of
conflict, the present disclosure will control.
INTRODUCTION
[0050] DEB patients lack functional collagen 7 due to mutations in
the COL7A1 gene
which encodes type VII collagen (also referred to as C7 or Col7). Col7 is
required to produce
anchoring fibrils necessary for epidermis-dermis adhesion. Endogenous Col7
forms through a
complex supramolecular aggregation process. Specifically, three alpha chains
associate
through their C-terminus ends to form a homo-trimer molecule, which folds into
a triple
helical conformation within the collagenous region. Two homo-trimers form anti-
parallel
dimers, from which the C-tcrminal propeptidcs arc protcolytically cleaved by
proteases such
as bone morphogenetic protein 1. Subsequently, a large number of these anti-
parallel dimers
laterally aggregate to form anchoring fibrils. Col7 acts as a major component
of the
anchoring fibrils enabling the attachment of the epidermis to the dermis. A
mutation in the
COL7A1 gene involved in DEB (e.g., RDEB) leads to aberrant synthesis of C7 or
defective
assembly of the protein into anchoring fibrils, resulting in poor epidermal-
dermal adherence.
[0051] Replacing the aberrant or missing protein with systemic,
intravenous-administered
collagen 7, such as a recombinant Col7 (rCol7), is predicted to allow
formation of anchoring
fibrils and therefore lead to correction of blistering abnormalities and
complications
throughout the body in patients with DEB (e.g., RDEB). Intravenous
administration of rCol7
in mice has been demonstrated to result in deposition of collagen 7 protein in
the skin and
improvement in wound healing (see, e.g., U.S. Patent Publication No.
US20140031295,
which is herein incorporated in reference in its entirety).
[0052] The present disclosure relates to a disease-modifying Col7
(e.g., rCol7, such as
rhCo17) replacement therapy for subjects with DEB, in particular subjects with
recessive
DEB (RDEB). A rCol7 composition (PTR-01) is developed by Applicant and used
for
treatment of patients with DEB, especially patients with RDEB. Systemic (e.g.,
intravenous)
delivery of rCol7 is believed to restore functional Col7 to the dermal-
epidermal basement
membrane zone (BMZ), thereby promoting the assembly of normal anchoring
fibrils,
providing stability to dermal-epidermal adhesion at the lamina densa/upper
papillary dennis
interface, and correcting blistering abnormalities and complications in
patients with DEB.
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DEFINITIONS
[0053] The terms used in this disclosure generally have their
ordinary meanings in the art,
within the context of this disclosure and in the specific context where each
term is used.
[0054] As used herein, the terms "Collagen 7," "Col7," "Collagen Type VII,"
and "C7" are
used interchangeably and refer to collagen 7 protein. Human Col7 (also
referred to herein as
hCo17) is a large extracellular protein with a mass of approximately 900
kilodaltons (kDa)
that is a major component of the anchoring fibrils enabling the attachment of
the epidermis to
the dermis. Col7 is a homo-trinaer consisting of three human collagen alpha-1
(Type VII)
polypeptides (alpha-1 chains). The alpha-1 chain (Type VII) is encoded by the
COL7A1 gene.
Each Co17 alpha-1 chain is 2928 amino acids in length and comprises a central
collagenous
domain flanked by two non-collagenous domains: the NC1 domain at the N-
terminus and the
NC-2 domain at the C-terminus. Three alpha-1 chains associate through their C-
terminal NC2
domains to form the homo-trimer molecule which folds into a triple-helical
conformation
within the collagenous region, which contains hydroxylated proline and lysine
residues. Two
homo-trimers lead to the fat __ -nation of an antiparallel dimer with the N-
terminus (NC1
domain) present at both ends of the anti-parallel dimer. Lateral assembly of
anti-parallel
dimers lead to the formation of the anchoring fibrils that are highly
specialized attachment
structures in the basement membrane zone (BMZ) and are critical for the
attachment of the
epidermis to the underlying dermis. These anchoring fibrils could also extend
from the
lamina densa of the BMZ to the upper papillary dermis within the dermal-
epidermal junction
in normal skin. The full-length alpha chain polypeptide of human Col7
comprises the amino
acid sequence of SEQ ID NO: 1 (Ref. NO.: NP_000085), which is naturally
encoded by the
nucleic acid sequence of SEQ ID NO: 2 (Ref. NO.: NM 000094). In the context of
the
present disclosure, Col7 may refer to recombinant collagen 7 protein, or a
functional variant
thereof. A functional variant of a rCol7 may have structural properties (e.g.,
anchoring fibril
formation), binding properties (e.g., binding to collagen IV and/or
fibronectin), and/or signal
transduction activities (e.g., tumor growth factor beta (TGF-beta) suppression
and/or
fibroblast growth factor 2 (FGF2) expression) equivalent to or substantially
similar to full
length Col7. As used herein, the term "recombinant human Col7 (rhCo17)" refers
to a
recombinant foul' of human Col7 having at least about 70%, at least about 75%,
at least
about 80%, at least about 85%, at least about 86%, at least about 87%, at
least about 88%, at
least about 89%, at least about 90%, at least about 91%. at least about 92%,
at least about
93%, at least about 94%, at least about 95%, at least about 96%, at least
about 97%, at least
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about 98%, at least about 99%, or about 100% identity to the amino acid
sequence of a native
human Col7 (e.g., SEQ ID NO: 1). A recombinant Col7 (e.g., rhCo17) may be made
by
recombinant techniques, such as made by recombinant DNA methods and produced
in a host
cell comprising a nucleotide sequence encoding Col7. The host cell may be a
mammalian
cell that provides necessary modifications to recombinant Col7.
[0055] As used herein, the terms -recombinant human collagen 7
substance,- -rhCol7
substance," and "rhC7 substance" are used interchangeably and refer to a
substance (e.g., a
drug substance) comprising a plurality of recombinant Col7 alpha polypeptides,
and/or
functional variants thereof. In some embodiments, an rhCol7 substance
comprises a
recombinant Col7 alpha polypeptide having an amino acid sequence of SEQ ID NO:
1. An
rhCol7 substance may be produced by host cells that are engineered to express
high levels of
recombinant Col7 and/or functional variants thereof. The rhCol7 substance may
be purified
from the culture media of the host cells. Suitable host cells may include
primary or
transformed cell lines, including, but not limited to, fibroblasts,
keratinocytes, CHO cells,
HEK293 cells, C127 cells, VERO cells, BHK cells, HeLa cells, COS cells, MDCK
cells, etc.
[0056] As used herein, the term "recombinant human Col7 (rhCol7)
drug product" refers
to a drug formulation comprising rhCol7 substance as the active ingredient. An
rhCol7 drug
product is formulated to maintain Col7 protein stability and is suitable for
clinical
administration by, for example, intravenous injection and/or infusion. An
rhCol7 drug
product may be a pharmaceutical composition comprising an rhCol7 substance.
[0057] As used herein, the term "protein therapy" refers to a
medical treatment that
supplements or replaces a protein in subjects in which that particular protein
is deficient or
absent. The protein may be introduced into the subject through gene therapy,
cell therapy,
and/or direct protein replacement. The tel
_______________________________________ la "protein replacement" refers to the
introduction
of a non-native, purified protein into a subject in which such protein is
deficient or absent.
The administered protein may be obtained from natural sources such as from
subjects having
normal protein, by, e.g., purification of protein from isolated tissue or
fluid such as placenta
and animal milk, or by recombinant protein expression. The purified,
recombinant protein
may be produced in vitro, e.g., using engineered cell lines. Protein
replacement therapy may
also refer to the introduction of a purified protein to a subject otherwise
requiring or
benefiting from administration of a purified protein, e.g., suffering from
protein insufficiency.
[0058] As used herein, the term "mutant protein" refers to a protein
translated from a gene
containing one or more genetic mutations that result in an altered protein
sequence, a
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truncated protein fragment, and/or complete absence of the protein. In
contrast, a "wild type"
or "native- protein refers to any protein encoded by a wild-type gene that is
capable of having
normal functional biological activity when expressed or introduced in vivo.
[0059] As used herein, the terms "wound" and "skin wound" refer to a breakdown
in the
protective function of the skin, such as the loss of continuity of epithelium
following injury to
the skin or underlying tissues caused by surgery, a cut, a laceration, a gash,
a tear, a scrape,
an abrasion, a scratch, a burn, chemical exposure, or as a result of a disease
such as DEB
(e.g., RDEB). A wound may have uniform or variable depth and morphology. A
wound can
be a chronic wound such as chronic open wound, a recurrent wound, a surgical
wound, a
blister, an ulcer, a non-healing wound, a scar, a surgical scar, or a scald.
In the context of the
present disclosure, wounds associated with DEB (e.g., RDEB) may be chronic
open wounds
and/or recurrent or acute wounds of different sizes. A chronic open wound
refers to an area
that does not heal and stays open for at least 12 weeks. A recurrent wound
refers to an area
that partially heals but then easily re-blisters. A wound may be disposed
anywhere on the
body, including on the torso, chest, abdomen, arms, hands, fingers, legs,
feet, toes, back,
buttocks, neck, or head. A wound may be discrete (e.g., having a definable
size or endpoints)
and/or may be continuous (e.g., extending across a swatch of skin and lacking
a definable
size or endpoints).
[0060] As used herein, the terms "disease" and "disorder" refer to a
pathological condition
of a part, organ, or system of an organism resulting from various causes, such
as autoimmune
defect, genetic defect, and/or environmental stress, and characterized by an
identifiable group
of signs or symptoms. As used herein, the term -genetic disease" may be a
disease that is
characterized by a protein deficiency. The protein deficiency may be caused by
genetic
mutations in a gene encoding such protein which causes absent, insufficient
amounts of, or
dysfunctional protein or may arise from the development of antibodies to the
protein. A
"skin disease" or "skin disorder" means a clinical condition of the skin, such
as a condition
that affects the skin in a subject, for example, a bullous disorder, an
inflammatory skin
condition, or a skin cancer. Bullous (blistering) disorders are a group of
heterogeneous
disorders characterized by elevated fluid-filled blistering lesions (bullae)
that primarily are on
the skin and mucous membranes. B ullae can be variable in sizes and the
specific symptoms
and severity of blistering diseases vary from one person to another, even
among individuals
with the same disorder. Exemplary blistering disorders include, but are not
limited to,
epidermolysis bullosa acquisita (EB A) and congenital epidermolysis bullosa
(EB) such as
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dystrophic EB. EB includes a group of inherited connective tissue diseases
that cause blisters
on the skin and mucous membranes resulting from genetic defects. DEB is mostly
caused by
mutations within the COL7A1 gene, which encodes Col7 protein. To date, about
800
mutations in the COL7A1 gene have been reported. DEB has two patterns of
inheritance:
autosomal dominant (Dominant DEB, DDEB) and autosomal recessive (Recessive
DEB,
RDEB). DDEB involves reduced Col7 expression which is generally caused by
glycine
substitutions within the collagenous domain of the collagen alphal (VII)
chain. RDEB is
usually severe and caused by absence or marked reduction of Col7 expression,
mostly due to
premature termination codons (FTC) in the COL7A1 gene. In some embodiments,
DEB (e.g.,
DDEB or RDEB) is diagnosed following a physical exam, laboratory test results
(e.g., based
on skin biopsy), review of medical history, and/or genetic testing. In some
embodiments,
diagnosis of DEB (e.g., DDEB or RDEB) is confirmed via genetic testing.
[0061] As used herein, the terms "patient" and "subject" refer to an
individual to be treated
according to the methods provided herein. A subject may be a human or a non-
human
mammal, such as a non-human primate, pig, goat, horse, cow, dog, cat, rat,
mouse, or rabbit.
A subject is preferably a human. A subject may be afflicted with a skin
disorder (e.g., a
genodermatosis) such as DEB (e.g., DDEB or RDEB). A subject may have
previously been
diagnosed with and optionally undergone a therapy for a skin disorder (e.g., a
genodermatosis) such as DEB (e.g., DDEB or RDEB). A subject may be known to
have a
genetic mutation associated with DEB. A subject may have one or more symptoms
or
complications associated with DEB, such as skin wounds including blistering,
itching, pain,
skin erosion. scarring, skin fragility, gangrene, aplasia or hypoplasia of the
skin,
hypopigmcntation of skin, milia, skin infections, cheilitis (e.g.,
inflammation of lips),
dystrophic fingernails or toenails, abnormal dental enamel, pseudosyndactyly
or
camptodactyly of fingers or toes, finger or toe syndactyly, flexion
contracture of toes,
carious teeth, dysphagia (e.g., poor swallowing), furrowed or grooved tongue,
esophageal
stricture, laryngeal stenosis, failure to thrive, dilated cardiomyopathy,
abnormal pulmonary
interstitial morphology, acute constipation, hearing or visual impairment,
eczema,
gh-llnerulcvathy, immunologic hypersensitivity, nasolacrimal duct obstruction,
anemia,
chronic ear infections, corneal erosion, corneal abrasion or scarring, oral
erosions,
microstomia, osteopenia, ectropion, immunologic hypersensitivity, nephrotic
syndrome,
phimosis, renal insufficiency, urinary retention, ureteral stenosis, stroke,
or squamous cell
carcinoma. In some embodiments, a subject has one or more symptoms or
complications
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associated with DEB selected from skin wounds including blistering, scarring,
gangrene,
aplasia or hypoplasia of the skin, hypopigmentation of skin, milia, skin
infections, cheilitis
(e.g., inflammation of lips), dystrophic fingernails or toenails, abnormal
dental enamel,
pseudo syndactyly or camptodactyly of fingers or toes, finger or toe
syndactyly, flexion
contracture of toes, carious teeth, dysphagia (e.g., poor swallowing),
furrowed or grooved
tongue, esophageal stricture, and laryngeal stenosis. In some embodiments, a
subject has one
or more symptoms or complications associated with DEB selected from skin
wounds
including blistering, scarring, aplasia or hypoplasia of the skin, cheilitis
(e.g., inflammation of
lips), dystrophic fingernails or toenails, pseudosyndactyly or camptodactyly
of fingers or
toes, and finger or toe syndactyly. A subject may be of any age or stage of
development. In
some embodiments, a subject is an infant or neonate. In some embodiments, a
subject is less
than about 24 months old, such as less than about 20, 18, 16, 14, 12, 10, 8,
6, 5, 4, 3, 2, or 1
month old. Tn some embodiments, a subject is at least about 24 months (e.g., 2
years) old,
such as about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 years
old. In some
embodiments, a subject is between about 2-5 years old, about 2-6 years old,
about 2-8 years
old, about 2-10 years old, about 6-10 years old. about 6-12 years old, about 6-
18 years old,
about 8-12 years old, about 8-18 years old, about 12-18 years old, about 2-13
years old, about
6-13 years old, about 13-18 years old, or any range therein. In some
embodiments, a subject
is at least 18 years old.
[0062] As used herein, the term "pharmaceutically acceptable" refers to
molecular entities
and compositions that are physiologically tolerable and do not typically
produce untoward
reactions when administered to a human. Preferably, as used herein, the term
-pharmaceutically acceptable" means approved by a regulatory agency of the
Federal or a
state government or listed in the U.S. Pharmacopeia or other generally
recognized
pharmacopeia for use in animals, and more particularly in humans, or generally
recognized as
safe for use in, e.g., parenteral products.
[0063] As used herein, the terms "therapeutically effective dose" and
"effective amount"
refer to the amount of the compound that is sufficient to result in a
therapeutic response. In
connection with Col7 protein therapy, the terms "therapeutically effective
dose" and
"effective amount" may refer to the amount of the Col7 substance (e.g., rhCol7
substance), or
drug product or pharmaceutical composition comprising the same, that is
sufficient to result
in a therapeutic response. A therapeutic response may be any response that a
user (e.g., a
clinician) will recognize as an effective response to the therapy. Thus, a
therapeutic response
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will generally be an amelioration of one or more symptoms and/or complications
of a disease
or disorder such as DEB (e.g., DDEB or RDEB), specifically, the amount capable
of
inhibition, to some extent, incurrence and/or severity of skin wound;
reduction in the number
of skin wounds; reduction in skin lesion size; inhibition including reduction,
slowing down,
or complete cessation of blistering; closure of chronic open wounds; increase
in the rate of
healing of wounds and blisters; alleviation of skin inflammation; and
enhancement of Col7
incorporation to the epidermis-dermis junctions.
[0064] As used herein, "treating," "treat," and "treatment" refer to
administering to a
subject having a disease or disorder, or a symptom or complication thereof, a
pharmaceutical
composition, such that at least one symptom or complication of the disease or
disorder is
reversed, cured, alleviated, ameliorated, eliminated, delayed, or decreased.
Treating EB (e.g.,
DEB such as DDEB or RDEB) in a subject refers to administering to the subject
having an
EB a pharmaceutical composition (e.g., a pharmaceutical composition comprising
an rhCol7
substance, as described herein) such that at least one symptom or complication
of the EB is
reversed, cured, alleviated, ameliorated, eliminated, delayed, or decreased.
The symptoms or
complications of an EB disease that may be targeted for treatment include, but
are not limited
to, skin wounds including blistering; itching; pain; lesions (e.g., rectal,
anal, urethral lesions
and/or mucosal lesions and/or lesions of squamous epithelial tissue); skin
erosion; scarring;
skin fragility; gangrene; aplasia or hypoplasia of the skin; hypopigmentation
of skin; milia;
skin infections; cheilitis (e.g., inflammation of lips); dystrophic
fingernails or toenails; lesions
of the gastrointestinal tract; contractures, e.g., flexion contractures (e.g.,
of the extremities);
pseudosyndactyly or camptodactyly of the hands or feet; carcinoma (e.g.,
squamous cell
carcinoma); bulla formation; nail and/or teeth deformities; constricted
esophagus; laryngeal
stenosis; furrowed or grooved tongue; abnormal dental enamel; carious teeth;
dysphagia (e.g.,
poor swallowing); eye disorders; hearing or visual impairment; anemia;
malnutrition;
secondary skin infection; sepsis; hoarse voice; urethral stenosis; phimosis;
corneal scarring or
erosion; corneal abrasion; oral erosions; microstomia; osteopenia;
malabsorption; dilated
cardiomyopathy; abnormal pulmonary interstitial morphology; acute
constipation; eczema;
gh-nnerulcvathy; immunologic hypersensitivity; nasolacrimal duct obstruction;
chronic ear
infections; ectropion; immunologic hypersensitivity; nephrotic syndrome,
phimosis; renal
insufficiency; urinary retention; ureteral stenosis; stroke; and failure to
thrive.
[0065] As used herein, the terms "preventing," "prevent," and "prevention"
refer to
administering to a subject a pharmaceutical composition, e.g., prior to a
clinical manifestation
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of an unwanted condition (e.g., disease or other unwanted state of the host
animal) so that it
protects the host against developing the unwanted condition or a symptom or
condition
thereof. "Preventing" a disease may also be referred to as "prophylaxis" or
"prophylactic
treatment." In the context of the present disclosure, one or more symptoms or
complications
associated with EB, such as skin blistering or scarring, may be prevented by
administration of
a pharmaceutical composition (e.g., a pharmaceutical composition comprising an
rhCol7
substance). Scarring in a subject with EB may result in one or more of the
following
symptoms: contractures, e.g., flexion contractures (e.g., of the extremities);
pseudosyndactyly
of the hands or feet; carcinoma (e.g., squamous cell carcinoma); rectal
lesions; mucosal
lesions; bulla formation; bulla formation post manual trauma; nail or teeth
deformities;
constricted esophagus; eye disorders, anemia, malnutrition; secondary skin
infection; sepsis;
hoarse voice; urethral stenosis; phimosis; corneal scarring; malabsorption;
and failure to
thrive. In some embodiments, a symptom or complication of an EB disease (e.g.,
DEB such
as DDEB or RDEB) that may be prevented by administration of a pharmaceutical
composition (e.g., a pharmaceutical composition comprising an rhCol7
substance) may be,
for example, skin wounds including blistering; itching; pain; lesions (e.g.,
rectal, anal,
urethral lesions and/or mucosal lesions and/or lesions of squamous epithelial
tissue); skin
erosion; scarring; skin fragility; gangrene; aplasia or hypoplasia of the
skin;
hypopigmentation of skin; milia; skin infections; cheilitis (e.g.,
inflammation of lips);
dystrophic fingernails or toenails; lesions of the gastrointestinal tract;
contractures, e.g.,
flexion contractures (e.g., of the extremities); pseudo syndactyly or
camptodactyly of the
hands or feet; carcinoma (e.g., squamous cell carcinoma); bulla formation;
nail and/or teeth
deformities; constricted esophagus; laryngeal stenosis; furrowed or grooved
tongue;
abnormal dental enamel; carious teeth; dysphagia (e.g., poor swallowing); eye
disorders;
hearing or visual impairment; anemia; malnutrition; secondary skin infection;
sepsis; hoarse
voice; urethral stenosis; phimosis; corneal scarring or erosion; corneal
abrasion; oral
erosions; microstomia; ostcopcnia; malabsorption; dilated cardiomyopathy;
abnormal
pulmonary interstitial morphology; acute constipation; eczema; glomerulopathy;
immunologic hypersensitivity; nasolacrimal duct obstruction; chronic ear
infections;
ectropion; immunologic hypersensitivity; nephrotic syndrome, phimosis; renal
insufficiency;
urinary retention; ureteral stenosis; stroke; and failure to thrive.
[0066] As used herein, the terms "improve," "increase," "reduce," and
"decrease." and
grammatical equivalents thereof, indicate modulation of values relative to a
baseline
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measurement, such as a measurement in the same individual prior to initiation
of the
treatment described herein, or a measurement in a control subject (or multiple
control
subjects) in the absence of the treatment described herein.
[0067] As used herein, the term "dosing interval" refers to the amount of time
that elapses
between multiple doses being administered to a subject (e.g., a human
patient). The dosing
interval may alternately be referred to herein as the dosing frequency (e.g.,
the frequency at
which a dose is administered to a subject). In some embodiments, a single
dosing interval is
used for the duration of therapy with a Col7 substance (e.g., rhCol7
substance). Such a
dosing interval may be considered to be -fixed- within a given dosing regimen.
In some
embodiments, multiple dosing intervals are used over the course of therapy
with a Col7
substance (e.g., rhCol7 substance). In some embodiments, a dosing interval is
less than about
one day, about one day, about 2 days, about 3 days, about 4 days, about 5
days, about 6 days,
about one week, about two weeks, about three weeks, about one month, about two
months,
about three months, about six months, or longer. In some embodiments, a dosing
interval is
an individualized interval that is determined for a given subject (e.g., human
patient) based
on, e.g., pharmacokinetic/toxicokinetic (PK/TK) data or other information
about that subject,
such as age, weight, height, body mass index, disease severity, comorbidities,
race, ethnicity,
national origin, genotype, and/or prior response to a Co17 replacement
therapy. An
individualized dosing interval may be the same dosing interval as for a fixed
dosing interval
(e.g., under another therapeutic scheme or for another subject) or may differ.
A therapeutic
regimen comprising administration of a Col7 substance (e.g., rhCol7 substance)
to a subject
may include multiple dosing regimens, one or more of which may comprise a
fixed dosing
interval and one or more of which may comprise an individualized dosing
interval, as
described herein. In some embodiments, a therapeutic regimen comprising
administration of
a Col7 substance (e.g., rhCol7 substance) to a subject includes a first dosing
regimen
comprising administration of the Col7 substance at a first dosing interval
(e.g., at a first
frequency), and a second dosing regimen comprising administration of the Col7
substance at
a second dosing interval (e.g., at a second frequency), where the first dosing
interval and the
second dosing interval are both fixed dosing intervals with different dosing
frequencies, and
where the first dosing regimen is performed before the second dosing regimen.
In some
embodiments, a therapeutic regimen comprising administration of a Col7
substance (e.g.,
rhCol7 substance) to a subject includes a first dosing regimen comprising
administration of
the Co17 substance at a first dosing interval (e.g., at a first frequency),
and a second dosing
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regimen comprising administration of the Co17 substance at a second dosing
interval (e.g., at
a second frequency), where the first dosing interval is a fixed dosing
interval and the second
dosing regimen is an individualized dosing interval, and where the first
dosing regimen is
performed before the second dosing regimen. In other embodiments, a
therapeutic regimen
comprising administration of a Col7 substance (e.g., rhCol7 substance) to a
subject includes a
first dosing regimen comprising administration of the Col7 substance at a
first dosing
interval, and a second dosing regimen comprising administration of the Col7
substance at a
second dosing interval, where the second dosing interval is a fixed dosing
interval and the
first dosing regimen is an individualized dosing interval, and where the first
dosing regimen
is performed before the second dosing regimen. In some embodiments, a dosing
regimen
includes administering a dose of a drug substance to a subject (e.g., a human
patient) more
than once per day, about once per day, about every 2 days, about every 3 days,
about every 4
days, about every 5 days, about every 6 days, about once a week, about every
other week,
about every three weeks, about once a month, about every two months, about
every three
months, about every six months, or less frequently.
[0068] As used herein, the term "clinical parameter" refers to a parameter of
a clinical
measurement. A clinical parameter may relate to a complication and/or symptom
associated
with DEB such as a size and number of skin wounds, duration of chronic open
wounds, the
rate of healing of wounds and blisters, etc. A clinical parameter may be
assessed by visual or
physical inspection, a biopsy, and/or a biochemical assay, such as an assay of
urine, blood, or
plasma.
DRUG SUBSTANCE AND COMPOSITIONS
Active substance: rhCol7
The present disclosure relates to intravenous rhCo17 replacement therapy to
treat cutaneous
and systemic manifestations of dystrophic epidermolysis bullosa (DEB),
particularly
recessive DEB (RDEB), in subjects. The active drug substance for systemically
treating a
clinical condition of DEB, is recombinant human collagen 7 protein (rhCol7).
As described
herein, anchoring fibrils formed by assembly of Col7 dimers facilitate the
attachment of the
epidermis to the underlying dermis. Pathogenic mutations in the gene encoding
collagen
alpha-1 (Type VII) chain polypeptide (COL7A1) lead to abnormal, decreased, or
a complete
absence of anchoring fibrils in the skin, resulting in DEB. This lack of
normal functioning
anchoring fibrils is responsible for cutaneous and non-cutaneous symptoms
including poor
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epidermal-dermal adherence, pronounced skin fragility, and severe blistering
in the skin and
mucosa in DEB patients.
[0069] The direct mechanistic link between the genetic defect or
absence of Col7 in
anchoring fibrils and DEB makes appropriate introducing native Col7 or
functional
equivalent, such as a recombinant Col7 (e.g., rhCol7) for treating DEB
patients. Previous
nonclinical data demonstrate that intravenous administration of rhCol7
distributes to and is
selectively retained at the dermal-epidermal BMZ, forms normal anchoring
fibrils, reverses
dermal-epidermal separation by providing stability to dermal-epidermal
adhesion at the
lamina densa/upper papillary dermis interface, and results in a statistically
significant
improvement in survival in a mouse model of DEB.
[0070] Specifically, RDEB is a devastating systemic disease with no effective
therapy.
Current therapies in development are unlikely to address significant
gastrointestinal/genitourinaly (GI/GU) morbidity, corneal, and oral
manifestations of DEB, or
development of squamous cell carcinoma (SCC), the major source of mortality.
No other
systemic disease modifying approaches are in development. Recombinant collagen
7 has
demonstrated a reasonably favorable toxicological profile, including all
observations related
to immune mediated response to "foreign" protein. Therefore, it is reasonable
that
intravenous delivery of rhCol7 will restore functional Col7 to the dermal-
epidermal BMZ.
The restoration may promote the assembly of normal anchoring fibrils,
providing stability to
dermal-epidermal adhesion at the lamina densa/upper papillary dermis interface
and correct
blistering abnormalities and complications in patients with DEB.
[0071] In accordance with the present disclosure, the active ingredient of the
drug
substance is a recombinant human alpha-1 chain homo-trimer of type VII
collagen. In some
embodiments, the active drug substance is a recombinant form of the Col7
protein produced
in engineered cells that are transfected with an expression plasmid encoding
the full-length
human collagen VII sequence.
[0072] In some embodiments, the alpha-1 chain (Type VII collagen) polypeptide
comprises
an amino acid sequence of SEQ ID NO: 1. In some embodiments, the alpha-1 chain
(Type
VII collagen) polypeptide consists of an amino acid sequence of SEQ ID NO: 1.
In some
embodiments, the alpha-1 (Type VII collagen) chain polypeptide may comprise an
amino
acid sequence that is about 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,
93%,
94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the sequence of SEQ ID NO:
1. In
some embodiments, the alpha-1 chain polypeptide may be encoded by a
polynucleotide
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comprising a nucleic acid sequence of SEQ ID NO: 2. The rhCo17 encoding
polynucleotide
sequence may be about 75%, 80%, 85%, 86%, 875, 88%, 89%, 90%, 91%, 92%, 93%,
94%,
95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 2. In
some
embodiments, the rhCol7 encoding polynucleotide sequence may be codon
optimized. Codon
optimization may serve to increase glycine content of the coding nucleotide
sequence. In
some embodiments, the rhCol7 encoding polynucleotide sequence comprises one or
more
modifications. In some embodiments, the one or more modifications increase the
stability of
the encoding polynucleotide.
[0073] In some embodiments, the rhCol7 substance comprises a plurality of
recombinant
Col7 alpha-1 chain polypeptides, and/or functional variants thereof.
[0074] In some embodiments, the rhCol7 substance is produced in a mammalian
cell line
engineered to express or manufacture rhCol7. In some embodiments, the rhCol7
substance is
produced using genetically modified mammalian cells. As used herein, the term
"genetically
modified" refers to cells that express a particular gene product following
introduction of a
nucleic acid comprising a coding sequence which encodes the gene product.
Introduction of
the nucleic acid may be accomplished by any method known in the art including
gene
targeting and homologous recombination. As used herein, the term also includes
cells that
have been engineered to express or overexpress an endogenous gene or gene
product not
normally expressed by such cell. In some embodiments, the rhCol7 substance is
produced in
mammalian cells such as CHO cells. The CHO cells may be modified to comprise a
polynucleotide encoding the alpha-1 chain (Type VII) and at least one
polynucleotide
encoding a protein that can increase the expression of the Col7 alpha-1 chain
in the host cells,
e.g., prolidase, prolyl 4-hydroxylase, and/or heat shock protein 47 (HSP 47).
The genetically
engineered cell line used to manufacture rhCol7 may be referred to as a Master
Cell Bank
(MCB). In one preferred embodiment, the rhCol7 production cells may be derived
from a
Chinese hamster ovary CHO-K1 host cell line which is transfected with plasmids
encoding
rhCo17 as well as the prolyl hydroxylase alpha and beta subunits to promote
proline
hydroxylation (P4H), a post-translational modification that stabilizes the
rhCol7 structure. In
some embodiments, the rhCol7 substance is produced by the master cells co-
expressing
rhCo17 and prolidase, as described in U.S. Patent No. 9.676,837, the contents
of which are
incorporated herein by reference in their entirety. In some embodiments, the
rhCol7
substance is produced by the master cells co-expressing rhCol7 and prolyl 4-
hydroxylase, as
described in International Patent Publication No. W02020025129, the contents
of which are
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incorporated herein by reference in their entirety. The rhCol7 substance may
be produced in
cell culture and purified using a series of chromatographic and filtration
steps, then processed
into drug product. Each lot of drug substance and drug product may be
evaluated for quality
and stability.
[0075] rhCol7 expressing MCB cells may be progressively expanded in vessels of
increasing size using batch and/or perfusion culture to reach a high cell
density in the
production bioreactors. Intermediate harvests from the production bioreactors
may be
collected daily and clarified. The clarified harvests may be concentrated,
frozen, and later
pooled for purification to generate the rhCol7 substance. The clarified,
concentrated harvest
pools may be purified using multiple chromatography processes. In some cases,
three
chromatography steps including mixed mode, cation exchange, and hydrophobic
interaction
chromatography unit operations may be used. For example, the recombinant
products may be
purified through purification processes including but not limited to
ultrafiltration/diafiltration
(UF/DF) membrane capture, CaptoCore, SP Sepharose, and polypropylene glycol
(PPG)
chromatography steps. The purification process may also include one or more
viral reduction
processes, such as three orthogonal viral reduction steps including UV-C and
detergent
(Triton X-100) viral inactivation steps as well as viral filtration (e.g.,
Asahi Planova 35N).
The processed rhCol7 substance is preferably free of viruses. The purified
product may be
concentrated and filtered (e.g., diafiltered) into a formulation buffer.
Polysorbate 20 may be
added to generate the final drug substance composition.
[0076] In some embodiments, a drug substance includes one or more salts,
surfactants,
buffers, amino acids (e.g., non-essential amino acids), cryoprotectants,
and/or chelating
agents. In some embodiments, a drug substance includes a non-essential amino
acid, which
non-essential amino acid is preferably arginine. In some embodiments, a drug
substance
includes a phosphate buffer, which phosphate buffer is preferably sodium
phosphate. In
some embodiments, a drug substance includes a chelating agent, which chelating
agent is
preferably sodium citrate. In some embodiments, a drug substance includes a
cryoprotectant,
which cryoprotectant is preferably a sugar such as sucrose. In some
embodiments, a drug
substance includes sodium chloride. In some embodiments, a drug substance
includes a
surfactant, a buffer, a non-essential amino acid, a cryoprotectant, and a
chelating agent. In
some embodiments, a drug substance includes sodium phosphate, sodium citrate,
arginine
(e.g., L-arginine), sucrose, sodium chloride, and polysorbate 20. In some
embodiments, a
drug substance includes 1.2 nag/mL recombinant rCol7 in 10 mM sodium
phosphate, 5 mM
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sodium citrate, 100 naM L-arginine, 1.7% sucrose (w/v), 70 mM sodium chloride,
and 0.05%
(v/v) polysorbate 20, pH 7.2. In some embodiments, the bulk drug substance is
0.2
micrometer (1.(m) filtered, filled into sterile containers, and stored at < -
60 C for the drug
production.
[0077] The rhCo17 substance is preferably free of microbial and fungal
adventitious agents.
The structural and functional characteristics of the rhCol7 substances may be
evaluated and
compared with native Col7 protein.
[0078] In some embodiments, rhCol7 substance is a systemic protein therapy to
be
delivered via the intravenous route.
Formulations and drug products
[0079] The drug products of the present disclosure contain at least one active
ingredient,
recombinant human Col7 (rhCol7). The rhCol7 substance may be produced using
MCB cells
as discussed herein. The rhCol7 substance may be included in the drug product
at a target
protein concentration of about 0.01 milligrams per milliliter (mg/mL) to 100
mg/mL, about
0.1 mg/mL to 100 mg/mL, about 0.5 mg/mL to 100 mg/mL, about 1 mg/mL to 100
mg/mL,
about 10 mg/mL to 100 mg/mL, about 0.01 mg/mL to 50 mg/mL, about 0.1 mg/mL to
50
mg/mL, about 0.5 mg/mL to 50 mg/mL, about 1 mg/mL to 50 mg/mL, about 0.01
mg/mL to
20 mg/mL, about 0.1 mg/mL to 20 mg/mL, about 0.5 mg/mL to 20 mg/mL, about 1
mg/mL
to 20 mg/mL, about 10 mg/mL to 50 mg/mL, about 0.01 mg/mL to 20 mg/mL, about
0.1
mg/mL to 20 mg/mL, about 0.5 mg/mL to 20 mg/mL, about 1 mg/mL to 20 mg/mL,
about
0.01 mg/mL to 10 mg/mL, about 0.1 mg/mL to 10 mg/mL, about 0.5 mg/mL to 10
mg/mL, or
about 1.0 mg/mL to 10 mg/mL. In some examples, the rhCol7 substance is
included in the
drug product at a target protein concentration of about 0.1 mg/mL, about 0.2
mg/mL, about
0.3 mg/mL, about 0.4 mg/mL, 0.5 mg/mL, about 0.6 mg/mL, about 0.7 mg/mL, about
0.8
mg/mL, about 0.9 mg/mL, about 1.0 mg/mL, about 1.1 mg/mL, about 1.2 mg/mL,
about 1.3
mg/mL, about 1.4 mg/mL. about 1.5 mg/mL, about 1.6 mg/mL, about 1.7 mg/mL,
about 1.8
mg/mL, about 1.9 mg/mL. about 2.0 mg/mL, about 2.1 mg/mL, about 2.2 mg/mL,
about 2.3
mg/mL, about 2.4 mg/mL. about 2.5 mg/mL, about 2.6 mg/mL, about 2.7 mg/mL,
about 2.8
mg/mL, about 2.9 mg/mL. about 3.0 mg/mL, about 3.5 mg/mL, about 4.0 mg/mL,
about 4.5
mg/mL, about 5.0 mg/mL. about 5.5 mg/mL, about 6.0 mg/mL, about 6.5 mg/mL,
about 7.0
mg/mL, about 7.5 mg/mL. about 8.0 mg/mL, about 8.5 mg/mL, about 9.0 mg/mL,
about 9.5
mg/mL, about 10 mg/mL, about 15 mg/mL, or about 20 mg/mL. In some embodiments,
the
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drug product contains recombinant human collagen VII (rhCol7) at a target
concentration of
1.2 mg/mL.
[0080] In some embodiments, the rhCol7 drug product comprises at least one
pharmaceutically acceptable excipient, including those commonly used in
parenteral
biopharmaceutical formulations. In some examples, the excipients added in the
present
rhCol7 drug products include. but are not limited to, sodium phosphate
dibasic, sodium
citrate dihydrate, sodium chloride, L-arginine HC1, sucrose, and polysorbate
20.
[0081] Buffers may be selected from phosphate buffered saline
(PBS), or other suitable
buffers. The buffer is suitable for the target pH range, excipients, and
surfactants. In some
examples, the rhCol7 drt.i.g product may have a pH ranging from about pH 6.8
to about pH
7.5. For example, the pH of the rhCol7 drug product may be about 6.6, about
6.7, about 6.8,
about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, or about
7.5.
[0082] The rhCol7 drug products provided herein may have significantly
improved
solubility and reduced viscosity at higher protein concentrations. In some
embodiments,
agents are added to increase the stability of the drug substance of the
product, including but
not limited to L-arOnine (e.g., 100 millimolar (mM) L-arginine), and sucrose.
[0083] In some embodiments, the rhCol7 formulation comprises about 5-200 mM,
about
10-150 mM, about 20-150 mM, about 50-150 mM about 50-100 mM, about 75-100 mM,
or
about 100 mM L-arginine.
[0084] In some embodiments, the rhCol7 formulation comprises about 10-100 mM,
about
75-100 mM, about 50-100 mM, about 15-75 mM, about 35-75 mM, about 50-75 mM, or
about 50mM sucrose.
[0085] In some embodiments, a surfactant is included in the rhCol7 drug
product. In some
embodiments, the surfactant is selected from the group consisting of
polysorbate 20,
polysorbate 40, polysorbate 60, polysorbate 80, and a combination thereof. In
some
embodiments, the surfactant is polysorbate 20. In some embodiments, the
polysorbate 20 is
present at a concentration ranging from approximately 0.01% to 0.2%, such as
from about
0.01% to 0.15%, about 0.01% to 0.1%, about 0.01% to 0.08%, or about 0.01% to
0.06%. In
some embodiments, the drug product includes 0.05% polysorbate 20.
[0086] The present drug products are formulated to provide formulation
conditions that
allow for acceptable freeze/thaw (FIT) performance and improved stability
profiles to support
storage at frozen conditions, e.g., either -20 C or at < -60 C.
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[0087] In some embodiments, the present rhCol7 drug product is ready-to-fill.
Therefore,
all drug product excipients are incorporated at the drug substance (i.e.,
rhCol7 production)
manufacturing stages, for example. the MCB cell culture and cultural media
harvest and
purification processes; there are no additional excipients added during the
rhCo17 drug
product manufacturing process.
[0088] In some embodiments, the rhCol7 drug product of the present disclosure
is sterile.
In some embodiments, the rhCol7 drug product of the present disclosure is free
of
preservatives.
[0089] In some embodiments, the rhCol7 drug product is manufactured using
aseptic
processing techniques. The drug product may be sterile-filtered into sterile,
depyrogenated
glass vials and stoppered and sealed in an ISO 5/Class 100/ Grade A area. In
process testing
may be performed to ensure the sterility through the entire manufacturing
process. The in-
process testing may include integrity testing of bioburden reduction (0.2
micrometer (pm)
filtration) pre- and/or post-use, bioburden testing prior to sterile
filtration, and/or endotoxin
testing. Environmental monitoring including particulates and microbial
monitoring, may also
be performed throughout the drug product manufacturing process.
[0090] In some embodiments, the rhCol7 drug product is directly
prepared/manufactured
from the rhCol7 substance from MCB cell cultures. In some embodiments, the
frozen rhCol7
substance (e.g., cultural media harvested from the MCB culture) is removed
from storage,
thawed (e.g., in temperature-controlled water bath), pooled, and mixed, and
subsequently
subjected to a bioburden reduction filtration through a 0.5/0.2 pm membrane
filter unit.
Sterile filtration of the pooled bulk drug product may be performed using two
consecutive
0.5/0.2 pm sterile filter units. The drug product may be aseptically filled
into sterile vials
(e.g., lOR glass vials with stopper and flip cap), which vials may then be
stoppered and
crimped. The filled vials may be 100% visually inspected and defect vials are
rejected. All
acceptable vials are labelled and packaged at room temperature and then stored
at -60 C.
[0091] In some embodiments, a drug formulation comprising recombinant human
Col7
(rhCol7) substance is in the form of a clear to slightly opalescent, colorless
solution. As a
non-limiting example, the rhCol7 drug product is PTR-01, in which the rhCol7
substance is
formulated to a target concentration of 1.2 mg/mL recombinant Col7 in 10 mM
sodium
phosphate, 5 mM sodium citrate, 100 mM L-arginine, 1.7% sucrose (w/v), 70 mM
sodium
chloride, and 0.05% (v/v) polysorbate 20 at pH 7.2. Additional examples of
rhCol7 drug
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products are described in International Patent Publication No. W02017112757,
which is
herein incorporated by reference in its entirety.
[0092] In some embodiments, the rhCo17 substance is formulated for systemic
administration. In some embodiments, the rhCol7 substance is formulated for
intravenous
administration such as intravenous infusion. In some embodiments, the rhCol7
drug product
is an injectable aqueous solution.
[0093] In some embodiments, an rhCol7 composition is supplied as a sterile,
preservative-
free, frozen liquid in 10 mL clear, borosilicate glass vials (10R, Type I
glass). Each vial may
have a 20 millimeter (mm) grey butyl rubber stopper and a 20 mm aluminum flip
cap. Each
vial may be filled with a target volume of 5.5 milliliter (mL) to ensure a
withdrawal volume
of at least 5.0 mL (i.e., a target weight of 6.0 mg dose) from each vial. Each
vial may be for
single use.
[0094] In some embodiments, the rhCol7 drug product is stored at <- 60 C and
stable for at
least 24 months at <- 60 C, or at least 32 months at <- 60 C, or at least 36
months at <- 60 C,
at least 42 months at <- 60 C, or at least 48 months at <- 60 C. In other
embodiments, the
rhCol7 drug product may be stored at -20 5 C and stable for at least 12
months at -20
C, or at least 18 months at -20 5 C, or at least 24 months at -20 5 C, or
at least 30
months at -20 5 C, or at least 36 months at -20 5 C. In other embodiments,
the rhCol7
drug product may be stored at 5 3 C and is stable for up to one month.
[0095] The present drug product may be clinically prepared as dosing solutions
before
intravenous injection or infusion. During clinical use, dosing solutions may
be prepared at
fixed volumes in sterile saline (0.9% sodium chloride) with a final dosing
solution volume of
about 10-1000 mL, about 20-1000 mL, about 40-1000 mL, about 50-1000 mL, about
100-
1000 mL, about 200-1000 mL, about 300-1000 mL, about 400-1000 mL, about 500-
1000
mL, about 10-500 mL, about 20-500 mL, about 40-500 mL, about 50-500 mL, about
100-500
mL, about 200-500 mL, about 300-500 mL. about 400-500 mL, about 10-300 mL,
about 20-
300 mL, about 40-300 mL, about 50-300 mL, about 100-300 mL, or about 200-300
mL, such
as about 10 mL, 20 mL, 30 mL, 40 mL, 50 mL, 60 mL, 70 mL, 80 mL, 90 mL, 100
mL, 150
mL, 200 mL, 250 mL, 300 mL, 350 mL, 400 mL, 450 mL, 500 mL, 600 mL, 700 mL,
800
mL, 900 mL, or 1000 mL. The dosing solution may be administered intravenously
with dose
preparation at the clinical or hospital center pharmacy. In some examples, the
dosing solution
may be prepared in an IV bag such as a PVC IV bag. The dosing solution may be
stable for
up to 24 hours of storage at ambient room temperature.
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DISEASES AND APPLICATIONS
[0096] The rCol7 substance, drug products, and compositions and methods of the
present
disclosure can provide prophylactic, palliative, or therapeutic relief of a
wound, disorder, or
disease of the skin in a subject, specifically a skin disorder caused by
deficiency in Co17, e.g.,
Dystrophic Epidermolysis Bullosa (DEB), including the two main subtypes:
recessive
dystrophic epidermolysis bullosa (RDEB) and dominant dystrophic epidermolysis
bullosa
(DDEB). Other skin disorders may include, but are not limited to, skin cancer,
psoriasis,
lichen planus, lupus, rosacea, eczema, cutaneous candidiasis, cellulitis,
impetigo, decubitus
ulcers, erysipelas, ichthyosis vulgaris, dermatomyositis, acrodermatitis,
stasis dermatitis,
burns, and Netherton syndrome.
[0097] In some embodiments, Recessive Dystrophic Epidermolysis Bullosa (RDEB)
includes all subtypes such as RDEB -generalized severe (formerly known as the
Hallopeau-
Siemens variant), RDEB-generalized other, RDEB-inversa, RDEB-pretibial, RDEB-
pruriginosa, RDE-centripetalis, and RDEB-bullous dermolysis of the newborn
(Soro L. et al.,
J. Anesthel Dermatol., 2015, 8(5): 41-46). In other embodiments, dominant
dystrophic
epidermolysis bullosa (DDEB) includes all subtypes such as DDEB-generalized,
DDEB-
acral, DDEB-pretibial, DDEB-pruriginosa, DDEB-nails only, and DDEB-bullous
dermolysis
of the newborn (Fine et al., J. Am. Acad. Dermatol. 2008; 58931-950).
[0098] The rhCo17 substance, drug products, and compositions provided herein
can provide
therapeutic relief, including alleviating, preventing, or preventing the
progression of one or
more complications and symptoms of DEB, especially RDEB, including cutaneous
and
systemic manifestations in patients.
[0099] In accordance with the present disclosure, use of the rhCol7
substance, drug
products, and compositions provided herein for therapeutically treating a
subject with RDEB
by systemic administration of an effective amount of the rhCol7 substance is
capable of
enhancing, increasing, augmenting, and/or supplementing the levels of a
collagen alpha-1
(type VII) chain polypeptide, particularly the levels of Co17 present at the
BMZ of the skin.
[0100] In some embodiments, the patient to be treated is diagnosed with RDEB.
The
patient may be diagnosed with RDEB by genetical diagnosis for mutations in the
COL7A1
gene.
[0101] In some embodiments, the subject is an adult. For example, the subject
may be at
least 18 years of age. In some embodiments, the subject is an elderly subject.
For example,
the subject may be at least 55 years of age, at least 60 years of age, at
least 65 years of age, at
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least 70 years of age, at least 75 years of age, or at least 80 years of age.
In some
embodiments, the subject is a pediatric subject that is less than 18 years of
age. In some
embodiments, a subject is less than about 24 months old, such as less than
about 20, 18, 16,
14, 12, 10, 8, 6, 5, 4, 3. 2, or 1 month old. In some embodiments, a subject
is at least about
24 months (e.g., 2 years) old, such as about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, or
18 years old. In some embodiments, a subject is between about 2-5 years old,
about 2-6 years
old, about 2-8 years old, about 2-10 years old, about 2-12 years old, about 6-
10 years old,
about 6-12 years old, about 6-18 years old, about 8-12 years old, about 8-18
years old, about
12-18 years old, about 2-13 years old, about 6-13 years old, about 13-18 years
old, or any
range therein. In some embodiments, a subject is at least 18 years old. In
some
embodiments, a subject is an infant or neonate (e.g., newborn). In some
embodiments, a
subject is less than about 24 months old, such as less than about 20, 18, 16,
14, 12, 10, 8, 6, 5,
4, 3, 2, or 1 month old. In some embodiments, a subject is less than about 1
year old. In
some embodiments, the pediatric subject is diagnosed with RDEB. In some
embodiments,
the newborn subject is diagnosed with RDEB.
[0102] In some embodiments, the subject to be treated has chronic wounds such
as chronic
open wounds and recurrent wounds. In some embodiments, the subject has chronic
open
wounds. In some embodiment, the subject has blisters. In other embodiments,
the subject has
recurrent wounds. In some embodiments, the subject has asplasia or hypoplasia
of the skin.
In some embodiments, the subject has pseudosyndactyly or camptodactyly of
fingers or toes,
and finger or toe syndactyly. In some embodiments, the subject has cheilitis.
In some
embodiments, the subject has dysphagia, furrowed or grooved tongue, esophageal
stricture,
and/or laryngeal steno sis. In some embodiments, the subject has chronic or
recurrent
wounds, blisters, aplasia of the skin, hypoplasia of the skin,
pseudosyndactyly or
camptodactyly of fingers or toes, finger or toe syndactyly, cheilitis,
dysphagia, furrowed or
grooved tongue, esophageal stricture, laryngeal stenosis, or a combination
thereof.
[0103] In some embodiments, the subject is suspected of having a mutation of
the COL7A1
gene. In some embodiments, the subject has undergone genetic testing to
confirm a COL7A1
mutation.
METHODS OF TREATING EPIDERMOLYSIS BULLOSA
[0104] The present disclosure provides methods of treating skin disorders such
as
dystrophic epidermolysis bullosa (DEB, such as RDEB), or symptoms or
complications
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thereof, using Col7 substances (e.g., rhCol7 substances). Treating a subject
according to a
method provided herein may result in a change such as an improvement in the
condition of
the subject, as measured by visual inspection, physical exam, laboratory exam,
self-reporting
by the subject, or any other useful measure. Treating a subject according to a
method
provided herein may result in amelioration, alleviation, reduction,
improvement, delay of
onset, delay of progression, elimination, and/or curing of one or more
symptoms or
complications of a skin disorder such as DEB (e.g., RDEB). The present
disclosure also
provides methods of ameliorating, alleviating, reducing, improving, delaying
onset of,
delaying progression of, eliminating, and/or curing one or more symptoms or
complications
of a skin disorder such as DEB. Symptoms and complications of DEB (e.g., RDEB)
may
include, for example, cutaneous and systemic symptoms. Symptoms and
complications of
DEB may include, for example, skin wounds including blistering, itching, pain,
skin erosion,
scarring, skin fragility, gangrene, aplasia or hypoplasia of the skin,
hypopigmentatic-m of skin,
milia, skin infections, cheilitis (e.g., inflammation of lips), dystrophic
fingernails or toenails,
abnormal dental enamel, pseudosyndactyly or camptodactyly of fingers or toes,
finger or toe
syndactyly, flexion contracture of toes, carious teeth, pysphagia (e.g., poor
swallowing),
furrowed or grooved tongue, esophageal stricture, laryngeal stenosis, failure
to thrive, dilated
cardiornyopathy, abnormal pulmonary interstitial morphology, acute
constipation, hearing or
visual impairment, eczema, glomerulopathy, immunologic hypersensitivity,
nasolacrimal
duct obstruction, anemia, chronic ear infections, corneal erosion, corneal
abrasion and
scarring, oral erosions, microstomia, osteopenia, ectropion, immunologic
hypersensitivity,
nephrotic syndrome, phimosis, renal insufficiency, urinary retention, ureteral
stenosis, stroke,
or squamous cell carcinoma.
[0105] In some embodiments, a method of treating DEB (e.g., RDEB), or a
symptom or
complication thereof, in a subject comprises administering to the subject a
Col7 substance
(e.g., rhCol7 substance). In some embodiments, the subject has been diagnosed
with DEB
(e.g., RDEB) or is at a risk of developing a severe skin disorder such as DEB.
[0106] In some embodiments, a method of treating DEB (e.g., RDEB), or a
symptom or
complication thereof, in a subject comprises administering to the subject a
therapeutically
effective amount of a rhCol7 drug product by systemic (e.g., intravenous)
administration. In
some embodiments, the rhCol7 drug product comprises recombinant human Col7
alpha-1
chain (Type VII) as active drug substance formulated in an injectable aqueous
solution. In
some embodiments, the rhCol7 drug product is PTR-01.
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[0107] In some embodiments, prior to receiving the rhCol7 protein therapy, a
subject with
DEB is prescreened and identified as suitable for treatment with the present
rhCol7 protein
therapy. Prescreening methods may include analyzing the genetic mutations in
the COL7A1
gene and/or measuring the Col7 deficiency at the dermal-epidermal junction by
immunofluorescence (IF) staining. The subject may be further evaluated for the
presence of
antibodies specific to Col7, e.g., Col7 neutralizing antibodies.
[0108] In some embodiments, the method further includes analyzing the genetic
mutations
in the COL7A1 gene in the subject to be treated (e.g., prior to initial
administration of rhCol7
protein therapy). In some embodiments, the method includes selecting a subject
for such
treatment on the basis that the subject carries a mutation in the COL7A1 gene
and is
consistent with a recessive inheritance pattern (i.e., RDEB). In one aspect,
the present
disclosure provides a method for treating a subject with RDEB, comprising: i)
identifying a
subject having a COL7A1 mutation consistent with a recessive inheritance
pattern; and ii)
administering a pharmaceutically effective amount of an rhCo17 drug product to
the subject
intravenously.
[0109] One or more parameters (e.g., complications and clinical symptoms
associated with
RDEB) may be assessed following administration of a rhCol7 protein therapy. In
some
embodiments, the one or more parameters are measured at the conclusion of a
defined dosing
period, such as an initial dosing interval. In some embodiments, the one or
more parameters
are measured at a defined duration of treatment, such as after 1 month, 3
months, 6 months, 1
year, 2 years, or more. In some embodiments, the one or more parameters are
compared to
assessments of the one or more parameters prior to initiation of rhCol7
protein therapy.
Assessment of the one or more parameters may be used to determine one or more
aspects of
the dosing regimen such as the dosage, dosing frequency, or duration. In some
embodiments,
the method further comprises performing or reviewing a serial photographic
quantitative
assessment of the wounds and blisters of the subject being treated. Such an
assessment may
evaluate, for example, wound suaface area (WSA), percent wound healing, and/or
time to re-
blistering and may be beneficial for subjects with RDEB given the chronic and
dynamic
nature of wounds in RDEB patients (Solis D. et al., J Invest Der/n(1101, 2018,
138,
Supplement: 97; doi.org/10.1016/j.jid.2018.03.580).
[0110] In some embodiments, rhCol7 treatment increases wound healing (e.g.,
the
frequency and/or completeness or sustainability of wound healing) in a subject
with RDEB.
In some embodiments, a wound of a subject heals faster while the subject is
under rhCol7
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than it would otherwise heal or had previously healed prior to commencement of
treatment.
In some embodiments, a wound of a subject heals more completely and/or more
sustainably
while the subject is under rhCo17 that it would otherwise heal or had
previously healed prior
to commencement of treatment. The wound may be a chronic open wound, and/or a
recurrent wound. In some embodiments, the wound healing is sustained. In some
embodiments, a majority of visible wounds or lesions are improved. In some
embodiments,
the improvement in a wound lesion is at least 2 levels according to a 7-point
Global
Impression of Change instrument (Table 1). In some embodiments, the
improvement in a
wound or lesion is assessed via visual inspection by a physician and/or
caregiver. In some
embodiments, the improvement in a wound or lesion is assessed via patient
interview or self-
evaluation.
[0111] In some embodiments, rhCol7 treatment increases the deposition of rCol7
into the
DEJ of the skin. The deposition of collagen 7 protein to the DEJ can induce
formation of
anchoring fibrils. Accordingly, the present disclosure further provides a
method of inducing
formation of anchoring fibrils in the skin, comprising administering rhCol7 to
the subject
(e.g., as described herein).
[0112] In some embodiments, rCol7 treatment can reduce the wound surface area
in a
subject, including wound surface area of target lesions and/or total body
wound surface area.
The wound surface area can be measured by imaging the wound areas. In some
embodiments, a skin wound reduces in size after rCol7 therapy. The size of a
skin wound
may be reduced by, for example, at least about 10%, 20%, 30%, 40%, 50%, 60%,
70%, 80%,
90%, or more. In some embodiments, a skin wound completely heals or closes in
response to
rCol7 therapy (e.g., the size is reduced by about 100%). In some embodiments,
the number
or abundance of skin wounds and lesions is reduced in a subject following
rCol7 therapy.
[0113] In some embodiments, rCol7 treatment improves skin integrity, as
assessed by, e.g.,
a decrease in suction blister time and/or location and/or an increase in time
to re-blistering.
[0114] In some embodiments, rCol7 treatment reduces pain associated with a
skin wound,
such as severity of pain and/or impact of pain on quality of life, which may
be evaluated by
the modified PROMIS subscales and iscorEB.
[0115] In some embodiments, rCol7 treatment reduces itch or irritation
associated with skin
wounds such as severity of itch or irritation and/or impact of itch or
irritation on quality of
life, which may be evaluated by the modified PROMIS subscales and iscorEB.
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[0116] In some embodiments, rCol7 treatment reduces or stabilizes systemic
features of
RDEB including dysphagia (e.g., as measured by Brief Esophageal Dysphagia
Scale and/or
oral nutritional intake), corneal symptoms (e.g., as measured by Eye Symptoms
Scale),
nutritional status (e.g., as measured by biomarkers Hgb/Hct, total
protein/albumin, and/or
Fe/TIBC), inflammation (e.g., as measured by markers for inflammation and/or
CRP),
fibrosis (e.g., as measured by fibrosis biomarkers). DEB associated activity,
and/or mental
health and social functioning.
[0117] In some embodiments, rCo17 treatment improves the overall quality of
life, overall
health, and disability of a subject with RDEB. In some embodiments,
improvement of
quality of life, health, and/or disability is measured by a patient interview
and/or self-
evaluation. In some embodiments, improvement of quality of life, health,
and/or disability is
measured by a caregiver interview and/or evaluation.
[0118] In some embodiments, rCoL7 treatment decreases pain associated with
RDEB,
decreases blister and/or wound formation, increases the rate of healing of
skin blisters and/or
skin wounds, increases the rate of wound closure, increases the percentage of
wound healing,
decreases time to re-blistering and/or rewound, increases skin integrity
(i.e., decrease in
likelihood of tearing or blistering due to mechanical or environmental
stress), decreases the
number of chronic blisters and/or wounds, decreases the wound surface area
including the
total wound area, decreases the number of concomitant medications required to
control
RDEB symptoms, decreases the number of blisters and/or wounds which become
infected,
decreases pruritus, decreases inflammation associated with RDEB, and/or
decreases infection
incidence. In some embodiments, rCol7 treatment reduces the risk of anemia
that is typically
associated with larger recurrent wound size and longer time to close the open
wounds in
subjects with RDEB.
Administration
[0119] The methods provided herein of, e.g., treating a skin disorder such as
DEB (e.g.,
RDEB or DDEB) and ameliorating, alleviating, reducing, improving, delaying
onset of,
delaying progression of, eliminating, and/or curing a symptom or complication
of a skin
disorder such as DEB may comprise systemic administration of a Col7 drug
substance (e.g.,
rhCol7 substance). Systemic administration is suitable for delivery rhCol7
protein to the
skin of the total body in the subject, as well as other areas of the body that
may be impacted
by a systemic skin disorder such as DEB (e.g., RDEB or DDEB).
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[0120] In some embodiments, systemic administration of a Co17 substance (e.g.,
rhCol7
substance) comprises intravenous injection or infusion. As a non-limiting
example, the
rhCo17 composition may be administered by slow infusion via an intravenous
route of
administration.
[0121] In some embodiments, the rhCol7 drug product is administered
by bolus injection,
slow push injection, or intravenous infusion. In some embodiments, the
administration is by
intravenous infusion over a period of time, e.g., less than about 6 hours,
less than about 5
hours, less than about 4 hours, less than about 3 hours, less than about 2
hours, less than
about 90 minutes, less than about 80 minutes, less than about 70 minutes, less
than about 60
minutes, less than about 50 minutes, less than about 45 minutes, less than
about 30 minutes,
less than about 20 minutes, or less than about 10 minutes. For example, the
intravenous
infusion may last about 1-10 minutes, about 1-5 minutes, about 3-10 minutes,
about 5-10
minutes, or 10-30 minutes. In some embodiments, the intravenous infusion lasts
about 30
minutes to 4 hours, such as about 30-60 minutes, about 30-90 minutes, about 1-
4 hours, about
1-3 hours, or about 2-4 hours.
[0122] In some embodiments, the rhCol7 protein therapy is administered at an
infusion rate
of 0.1 mg/kg/minutes to 5.0 mg/kg/minute, such as about 0.1 mg/kg/minute, 0.2
mg/kg/minute, 0.3 mg/kg/minute, 0.4 mg/kg/minute, 0.5 mg/kg/minute, 0.6
mg/kg/minute,
0.7 mg/kg/minute, 0.8 mg/kg/minute, 0.9 mg/kg/minute, 1.0 mg/kg/minute, 1.1
mg/kg/minute, 1.2 mg/kg/minute, 1.3 mg/kg/minute, 1.4 mg/kg/minute, 1.5
mg/kg/minute,
1.6 mg/kg/minute, 1.7 mg/kg/minute, 1.8 mg/kg/minute, 1.9 mg/kg/minute, 2.0
mg/kg/minute, 2.5 mg/kg/minute, 3.0 mg/kg/minute, 3.5 mg/kg/minute, 4.0
mg/kg/minute,
4.5 mg/kg/minute, or 5.0 mg/kg/minute.
Dosing Regimen
[0123] In some embodiments, more than one dose of a rhCol7 drug
product is
administered to a subject. In some embodiments, a dosing interval (e.g., time
between doses
during a dosing regimen) is less than about one day, about one day, about 2
days, about 3
days, about 4 days, about 5 days, about 6 days, about one week, about two
weeks, about three
weeks, about one month, about two months, about three months, about six
months, about one
year, or longer. In some embodiments, the subject is administered a defined
number of doses
of a rhCol7 substance in a defined period of time. For example, the subject
may receive 2, 3,
4, 5, 6, 7, 8, 9, 10 or more doses over a defined period of time, such as
during a one week,
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two week, three week, four week, five week, six week, month long, year long,
or other
period.
[0124] In some embodiments, rhCo17 treatment lasts at least about
one month, such as at
least about three months, four months, five months, six months, one year, two
years, three
years, or longer. In some embodiments, rhCo17 treatment lasts the lifetime of
the subject.
[0125] In some embodiments, dosing is weight-based dosing. In some
embodiments, an
rhCo17 substance is administered at a dose of about 0.01 milligrams of drug
substance per
kilogram of subject (mg/kg) to 50 mg/kg, such as about 0.05 mg/kg to 50 mg/kg,
about 0.1
mg/kg to 50 mg/kg. about 0.5 mg/kg to 50 mg/kg, about 1 mg/kg to 50 mg/kg,
about 5 mg/kg
to 50 mg/kg, about 0.01 mg/kg to 20 mg/kg, about 0.1 mg/kg to 20 mg/kg, about
0.5 mg/kg
to 20 mg/kg, about 1 mg/kg to 20 mg/kg, about 0.01 mg/kg to 10 mg/kg, about
0.1 mg/kg to
mg/kg, about 0.5 mg/kg to 10 mg/kg, about 1 mg/kg to 10 mg/kg, about 3 mg/kg
to 10
mg/kg, about 0.01 mg/kg to 5 mg/kg, about 0.1 mg/kg to 5 mg/kg, about 0.3
mg/kg to 5
mg/kg, about 0.5 mg/kg to 5 mg/kg, about 1.0 mg/kg to 5.0 mg/kg, about 3.0
mg/kg to 5.0
mg/kg, about 0.01 mg/kg to 3 mg/kg, about 0.1 mg/kg to 3 mg/kg, about 0.3
mg/kg to 3
mg/kg, about 0.5 mg/kg to 3 mg/kg, about 1 mg/kg to 3 mg/kg, or any useful
range therein. In
some embodiments, an rhCo17 substance is administered at a dose of between
about 0.3
mg/kg to about 5 mg/kg. In some embodiments, an rhCol7 substance is
administered at a
dose of about 0.01 mg/kg, about 0.03 mg/kg, about 0.05 mg/kg, about 0.1 mg/kg,
about 0.2
mg/kg, about 0.3 mg/kg, about 0.4 mg/kg, about 0.5 mg/kg, about 0.6 mg/kg,
about 0.7
mg/kg, about 0.8 mg/kg, about 0.9 mg/kg, about 1.0 mg/kg, about 1.1 mg/kg,
about 1.2
mg/kg, about 1.3 mg/kg, about 1.4 mg/kg, about 1.5 mg/kg, about 1.6 mg/kg,
about 1.7
mg/kg, about 1.8 mg/kg, about 1.9 mg/kg. about 2.0 mg/kg, about 2.1 mg/kg,
about 2.2
mg/kg, about 2.3 mg/kg, about 2.4 mg/kg. about 2.5 mg/kg, about 2.6 mg/kg,
about 2.7
mg/kg, about 2.8 mg/kg, about 2.9 mg/kg, about 3.0 mg/kg, about 3.1 mg/kg,
about 3.2
mg/kg, about 3.3 mg/kg, about 3.4 mg/kg, about 3.5 mg/kg, about 3.6 mg/kg,
about 3.7
mg/kg, about 3.8 mg/kg, about 3.9 mg/kg, about 4.0 mg/kg, about 4.5 mg/kg,
about 5.0
mg/kg, about 6.0 mg/kg, about 7.0 mg/kg, about 8.0 mg/kg, about 9.0 mg/kg,
about 10
mg/kg, about 15 mg/kg, or about 20 mg/kg.
[0126] In some embodiments, the rhCol7 protein treatment includes
thawing and diluting
a frozen or lyophilized rhCol7 substance with a pharmaceutically acceptable
carrier such as a
sterile saline solution suitable for intravenous injection, thereby forming a
drug solution; and
withdrawing a volume of drug solution to provide a pre-selected dose, e.g., a
dose of about
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0.01 mg/kg, about 0.03 mg/kg, about 0.05 mg/kg, about 0.1 mg/kg, about 0.2
mg/kg, about
0.3 mg/kg, about 0.4 mg/kg, about 0.5 mg/kg, about 0.6 mg/kg, about 0.7 mg/kg,
about 0.8
mg/kg, about 0.9 mg/kg, about 1.0 mg/kg. about 1.1 mg/kg, about 1.2 mg/kg,
about 1.3
mg/kg, about 1.4 mg/kg, about 1.5 mg/kg, about 1.6 mg/kg, about 1.7 mg/kg,
about 1.8
mg/kg, about 1.9 mg/kg, about 2.0 mg/kg, about 2.5 mg/kg, about 2.6 mg/kg,
about 2.7
mg/kg, about 2.8 mg/kg, about 2.9 mg/kg, about 3.0 mg/kg, about 3.1 mg/kg,
about 3.2
mg/kg, about 3.3 mg/kg, about 3.4 mg/kg, about 3.5 mg/kg, about 3.6 mg/kg,
about 3.7
mg/kg, about 3.8 mg/kg, about 3.9 mg/kg, about 4.0 mg/kg, about 4.5 mg/kg,
about 5.0
mg/kg, about 6.0 mg/kg, about 7.0 mg/kg. about 8.0 mg/kg, about 9.0 mg/kg,
about 10
mg/kg, about 15 mg/kg, or about 20 mg/kg.
[0127] In some embodiments, a suitable saline solution contains
sodium chloride. In some
examples, sodium chloride is present at a concentration ranging from
approximately 0-2%
(e.g., from approximately 0-1.5% or 0-1.0%). In some embodiments, the sodium
chloride is
present at a concentration of approximately 0.1%, 0.2%, 0.3%, 0.4%, 0.5%,
0.6%, 0.7%,
0.8%,0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or
2.0%. In
some embodiments, the saline solution is present at a concentration of more
than about 2.0%.
In one example, the rhCol7 drug product is diluted in 0.9% saline forming drug
solution for
administration.
[0128] In some embodiments, a single dosing interval is used over
the course of therapy
with a Col7 substance (e.g., rhCol7 substance). In some embodiments, multiple
dosing
intervals are used over the course of therapy with a Col7 substance (e.g.,
rhCol7 substance).
In some embodiments, a dosing interval is fixed. In some embodiments, a dosing
interval is
an individualized interval that is determined for a given subject based on,
e.g.,
pharmacokinetic/toxicokinetic (PK/TK) data or other information about that
subject, such as
age, weight, height, body mass index, disease severity, comorbidities, race,
ethnicity, national
origin, genotype, and/or prior response to a Col7 replacement therapy. An
individualized
dose and dosing interval combination may be the same as those for fixed
interval regimens or
may differ. In some embodiments, the subject initially receives a fixed dosing
interval for the
first two or more doses, and then changes to an individualized dosing interval
depending on a
follow-up measurement after the initial dosing. Alternatively, the regimen may
initially be at
an individualized dosing interval, and then it may change to a fixed dosing
interval.
[0129] In some embodiments, a single dose level is used over the
course of therapy with a
Col7 substance (e.g., rhCol7 substance). In some embodiments, multiple dose
levels are used
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over the course of therapy with a Co17 substance (e.g., rhCol7 substance). In
some
embodiments, the dosing corresponding to a first dosing interval of a first
dosing regimen is
different from the dosing corresponding to a second dosing interval of a
second dosing
regimen. In some embodiments, a first dosing regimen comprises dosing the
subject at a first
dose level and with a first dosing interval and a second dosing regimen
comprises dosing the
subject at a second dose level and with a second dosing interval, where the
first dose level
and second dose level are the same. In some embodiments, a first dosing
regimen comprises
dosing the subject at a first dose level and with a first dosing interval and
a second dosing
regimen comprises dosing the subject at a second dose level and with a second
dosing
interval, where the first dose level and second dose level are different. In
some embodiments,
the first dosing regimen precedes the second dosing regimen, and the first
dose level is lower
than the second dose level. In some embodiments, the first dosing regimen
precedes the
second dosing regimen, and the first dose level is higher than the second dose
level. in some
embodiments, the first dosing regimen precedes the second dosing regimen, and
the first
dosing interval is shorter than the second dosing interval. In some
embodiments, the first
dosing regimen precedes the second dosing regimen, and the first dosing
interval is longer
than the second dosing interval.
[0130] In some embodiments, a method of treating a skin disorder
(e.g., DEB, such as
RDEB or DDEB), or ameliorating, alleviating, reducing, improving, delaying
onset of,
delaying progression of, eliminating, and/or curing a symptom or complication
of a skin
disorder such as DEB, comprises administering a Col7 substance (e.g., rhCol7
substance)
according to a first dosing regimen and a second dosing regimen, wherein: i)
the first dosing
regimen includes administering a first therapeutically effective amount of the
substance
according to a first dosing interval; and ii) the second dosing regimen
includes administering
a second therapeutically effective amount of the substance according to a
second dosing
interval. Administration according to the first dosing regimen may take place
prior to
administration according to the second dosing regimen. The first dosing
regimen may be
referred to as a "loading phase" and the second dosing regimen may be referred
to as a
"maintenance phase." In some embodiments, the first therapeutically effective
amount is
greater than the second therapeutically effective amount. In some embodiments,
the first
therapeutically effective amount is less than the second therapeutically
effective amount. In
some embodiments, the first therapeutically effective amount is the same as
the second
therapeutically effective amount. In some embodiments, the first dosing
interval is the same
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as the second dosing interval. In some embodiments, the first dosing interval
is longer than
the second dosing interval (e.g., the first dosing frequency is lower than the
second dosing
frequency). In some embodiments, the first dosing interval is shorter than the
second dosing
interval (e.g., the first dosing frequency is higher than the second dosing
frequency). In some
embodiments, the first dosing interval is a fixed dosing interval and the
second dosing
interval is an individualized dosing interval. In some embodiments, the first
dosing interval
is an individualized dosing interval and the second dosing interval is a fixed
dosing interval.
In some embodiments, the first dosing interval and the second dosing interval
are both fixed
dosing intervals. In some embodiments, the second dosing regimen lasts longer
than the first
dosing regimen. In some embodiments, the first dosing regimen lasts longer
than the second
dosing regimen.
[0131] In some embodiments, the first dosing regimen comprises
administering at least
one dose of the substance to the subject, such as at least 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13,
14, 15, or more doses to the subject. In some embodiments, the first dosing
regimen
comprises administering the Col7 substance to the subject at least once per
week, such as at
least 2, 3, 4, 5, 6, or 7 times per week. In some embodiments, the first
dosing interval is 1
day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days (e.g., 1 week), 2 weeks, 3
weeks, or 4
weeks. In some embodiments, the first dosing regimen comprises administering
the Col7
substance to the subject once per week. In some embodiments, the first dosing
regimen
comprises administering the Col7 substance to the subject less than once per
week, such as
once every two weeks, once every three weeks, or once every four weeks. In
some
embodiments, the first dosing regimen lasts 1-12 weeks, such as 1, 2, 3, 4, 5,
6, 7, 8, 9, 10,
1 1 , or 12 weeks. In some embodiments, the first dosing regimen comprises
administering a
dose of between about 0.1-50 mg/kg, such as about 0.1 mg/kg, about 0.2 mg/kg,
about 0.3
mg/kg, about 0.4 mg/kg, about 0.5 mg/kg. about 0.6 mg/kg, about 0.7 mg/kg,
about 0.8
mg/kg, about 0.9 mg/kg, about 1.0 mg/kg, about 1.1 mg/kg, about 1.2 mg/kg,
about 1.3
mg/kg, about 1.4 mg/kg, about 1.5 mg/kg, about 1.6 mg/kg, about 1.7 mg/kg,
about 1.8
mg/kg, about 1.9 mg/kg, about 2.0 mg/kg, about 2.1 mg/kg, about 2.2 mg/kg,
about 2.3
mg/kg, about 2.4 mg/kg, about 2.5 mg/kg, about 2.6 mg/kg, about 2.7 mg/kg,
about 2.8
mg/kg, about 2.9 mg/kg, about 3.0 mg/kg, about 3.1 mg/kg, about 3.2 mg/kg,
about 3.3
mg/kg, about 3.4 mg/kg, about 3.5 mg/kg, about 3.6 mg/kg, about 3.7 mg/kg,
about 3.8
mg/kg, about 3.9 mg/kg, about 4.0 mg/kg. about 4.1 mg/kg, about 4.2 mg/kg,
about 4.3
mg/kg, about 4.4 mg/kg, about 4.5 mg/kg, about 4.6 mg/kg, about 4.7 mg/kg,
about 4.8
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mg/kg, about 4.9 mg/kg, about 5.0 mg/kg, about 5.2, about 5.4 mg/kg mg/kg,
about 5.6
mg/kg, about 5.8 mg/kg, about 6.0 mg/kg, about 6.2 mg/kg, about 6.4 mg/kg,
about 6.6
mg/kg, about 6.8 mg/kg, about 7.0 mg/kg. about 7.5 mg/kg, about 8.0 mg/kg,
about 8.5,
about 9.0 mg/kg mg/kg, about 9.5 mg/kg, about 10.0 mg/kg, about 11.0 mg/kg,
about 12.0
mg/kg, about 13.0 mg/kg, about 14.0 mg/kg, about 15.0 mg/kg, about 20.0 mg/kg,
about 25.0
mg/kg, about 30.0 mg/kg, about 35.0 mg/kg, about 40.0 mg/kg, about 45.0 mg/kg,
or about
50.0 mg/kg of the Col7 substance.
[0132] In some embodiments, the second dosing regimen comprises
administering at least
one dose of the substance to the subject, such as at least 2, 3,4, 5,6, 7, 8,
9, 10, 11, 12, 13,
14, 15, 20, 25, 30, 35, 40, 45, 50, 52, 60, 70, SO, 90, 100, or more doses to
the subject. In
some embodiments, the second dosing regimen lasts at least about 1 month, such
as at least
about 1, 3, 6, 8, 9, 12, 18, 24, 36, or more months. In some embodiments, the
second dosing
regimen lasts from its commencement to the end of the subject's lifetime. In
some
embodiments, the second dosing regimen comprises administering the Col7
substance to the
subject about every day, about every 2 days, about every 3 days, about every 4
days, about
every 5 days, about every 6 days, about once a week, about every other week,
about every
three weeks, about once a month, about every two months, about every three
months, about
every six months, or less frequently. In some embodiments, the second dosing
interval is 1
day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days (e.g., 1 week), 2 weeks, 3
weeks, 4 weeks,
1 month, 2 months, 3 months, 6 months, or longer. In some embodiments, the
second dosing
regimen comprises administering the Co17 substance to the subject about every
other week.
In some embodiments, the second dosing regimen comprises administering the
Col7
substance to the subject about every four weeks. In some embodiments, the
second dosing
regimen comprises administering a dose of between about 0.1-50 mg/kg, such as
about 0.1
mg/kg, about 0.2 mg/kg, about 0.3 mg/kg, about 0.4 mg/kg, about 0.5 mg/kg,
about 0.6
mg/kg, about 0.7 mg/kg, about 0.8 mg/kg, about 0.9 mg/kg, about 1.0 mg/kg,
about 1.1
mg/kg, about 1.2 mg/kg, about 1.3 mg/kg, about 1.4 mg/kg, about 1.5 mg/kg,
about 1.6
mg/kg, about 1.7 mg/kg, about 1.8 mg/kg, about 1.9 mg/kg, about 2.0 mg/kg,
about 2.1
mg/kg, about 2.2 mg/kg, about 2.3 mg/kg, about 2.4 mg/kg, about 2.5 mg/kg,
about 2.6
mg/kg, about 2.7 mg/kg, about 2.8 mg/kg, about 2.9 mg/kg, about 3.0 mg/kg,
about 3.1
mg/kg, about 3.2 mg/kg, about 3.3 mg/kg, about 3.4 mg/kg, about 3.5 mg/kg,
about 3.6
mg/kg, about 3.7 mg/kg, about 3.8 mg/kg. about 3.9 mg/kg, about 4.0 mg/kg,
about 4.1
mg/kg, about 4.2 mg/kg, about 4.3 mg/kg, about 4.4 mg/kg, about 4.5 mg/kg,
about 4.6
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mg/kg, about 4.7 mg/kg, about 4.8 mg/kg, about 4.9 mg/kg, about 5.0 mg/kg,
about 5.2
mg/kg, about 5.4 mg/kg, about 5.6 mg/kg, about 5.8 mg/kg, about 6.0 mg/kg,
about 6.2
mg/kg, about 6.4 mg/kg, about 6.6 mg/kg. about 6.8 mg/kg, about 7.0 mg/kg,
about 7.5
mg/kg, about 8.0 mg/kg, about 8.5 mg/kg, about 9.0 mg/kg, about 9.5 mg/kg,
about 10.0
mg/kg, about 11.0 mg/kg, about 12.0 mg/kg, about 13.0 mg/kg, about 14.0 mg/kg,
about 15.0
mg/kg, about 20.0 mg/kg, about 25.0 mg/kg, about 30.0 mg/kg, about 35.0 mg/kg,
about 40.0
mg/kg, about 45.0 mg/kg, or about 50.0 mg/kg of the Col7 substance.
[0133] In some embodiments, the second therapeutically effective amount and/or
second
dosing interval of the second dosing regimen are determined at least in part
based on an
assessment of the subject during or after the first dosing regimen. In some
embodiments, the
method further comprises, prior to the second dosing regimen, assessing the
subject to, e.g.,
assess the effectiveness of the Col7 substance and/or the response of the
subject to the Col7
substance. In some embodiments, the method further comprises assessing one or
more
clinical parameters during the first dosing regimen, during the second dosing
regimen, and/or
between the first and second dosing regimens.
[0134]
The methods provided herein may include a first dosing regimen (loading
phase)
and a second dosing regimen (maintenance phase). The loading dosing phase at
the
beginning of a treatment may comprise an initial intensive period at least in
part because of
the profound deficit of endogenous collagen 7 in subjects with DEB (e.g.,
RDEB). Without
wishing to be bound by theory, the intensive loading dosing regimen may
provide a sufficient
amount of rhCol7 to the skin to increase fibril formation. In some
embodiments, the loading
dosing regimen comprises administration of one dose of the rCol7 composition
twice daily,
every day, every other day, every three days, every four days, every five
days, every six days,
every week, or every other week. In some embodiments, the loading dosing
regimen includes
two, three, four, five, six or more doses, for example, the loading dosing
regimen may
include three or more doses, or four or more doses, or five or more doses. In
some
embodiments, the loading dosing regimen lasts for at least 1 week, 2 weeks, 3
weeks, 4
weeks, 5 weeks. 6 weeks, 1 month, 2 months, 3 months, or longer. In some
embodiments,
the loading dose is about 3 mg/kg rhCo17.
[0135]
The maintenance dosing regimen may involve less frequent dosing of the
subject
than the loading dosing regimen. In some embodiments, the maintenance dosing
regimen
comprises administration of one dose of the rCol7 composition every day, every
other day,
every three days, every four days, every five days, every six days, weekly,
every other week,
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every three weeks, every four weeks, every month, every two months, every
three months,
every four months, every five months, every six months, or every year. The
rCol7 drug
product may be administered at the same dose or alternatively different doses,
in the loading
and maintenance phases. As a non-limiting example, the dose at the loading
dosing phase is
about 3.0 mg/kg and the dose administered at the maintenance dosing phase is
about 3.0
mg/kg. The maintenance period may last four months, five months, six months,
seven
months, eight months, nine months, ten months, eleven months, one year, one
and half years,
two years, five years, ten years, or longer, such as for the life of the
patient.
[0136] In some embodiments, a dosing regimen (e.g., the first dosing regimen
and/or the
second dosing regimen) including dose frequency, dose, and duration time is
personalized
according to the subject's reaction, side effects, and treatment efficacy. In
some
embodiments, a dosing regimen (e.g., the first dosing regimen and/or the
second dosing
regimen) including dose frequency, dose, and duration time is fixed (e.g., not
individualized
based on details of the subject).
[0137] In some embodiments, the treatment regimen comprises administration of
the rCol7
composition to the patient with RDEB at least one loading dose of about 3.0
mg/kg daily,
twice daily, thrice daily, or weekly, and at least one maintenance dose of
about 3.0 mg/kg
weekly. In some embodiments, the dosing interval of the loading phase is about
one day. In
some embodiments, the dosing interval of the loading phase is about one week.
[0138] In some embodiments, the treatment regimen comprises administration of
the rCol7
composition to the patient with RDEB at least one loading dose of about 3.0
mg/kg daily,
twice daily, thrice daily, or weekly, and at least one maintenance dose of
about 3.0 mg/kg
biweekly. In some embodiments, the dosing interval of the loading phase is
about one day.
In some embodiments, the dosing interval of the loading phase is about one
week.
[0139] In some embodiments, the treatment regimen comprises administration of
the rCol7
composition to the patient with RDEB at least one loading dose of about 3.0
mg/kg daily,
twice daily, thrice daily, or weekly and at least one maintenance dose of
about 3.0 mg/kg
monthly. In some embodiments, the dosing interval of the loading phase is
about one day. In
some embodiments, the dosing interval of the loading phase is about one week.
[0140] In some embodiments, the treatment regimen comprises administration of
the rCol7
composition to the patient with RDEB at least one loading dose of about 3.0
mg/kg daily,
twice daily, thrice daily, or weekly and at least one maintenance dose of
about 3.0 mg/kg at
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every two months. In some embodiments, the dosing interval of the loading
phase is about
one day. In some embodiments, the dosing interval of the loading phase is
about one week.
[0141] In some embodiments, the treatment regimen comprises administration of
the rCol7
composition to the patient with RDEB at least one loading dose of about 3.0
mg/kg daily,
twice daily, thrice daily, or weekly and at least one maintenance dose of
about 3.0 mg/kg at
every three months. In some embodiments, the dosing interval of the loading
phase is about
one day. In some embodiments, the dosing interval of the loading phase is
about one week.
[0142] In some embodiments, the methods of the present disclosure comprise
intravenously
administering to a subject a Col7 substance (e.g., rhCol7 substance) according
to a first
dosing regimen and a second dosing regimen, where the first dosing regimen
comprises (i)
administration of a first loading dose of about 0.1-5.0 mg/kg, about 0.3-5.0
mg/kg, about 0.5-
5.0 mg/kg, about 1.0-5.0 mg/kg, about 0.1-3.0 mg/kg, about 0.3-3.0 mg/kg,
about 0.5-3.0
mg/kg, or about 1.0-3.0 mg/kg, such as about 0.1 mg/kg, about 0.3 mg/kg, about
0.5 mg/kg,
about 1.0 mg/kg, about 3.0 mg/kg, or about 5.0 mg/kg, of the Col7 substance on
the first day
of treatment; (ii) administration of a second loading dose of about 0.1-5.0
mg/kg, about 0.3-
5.0 mg/kg, about 0.5-5.0 mg/kg, about 1.0-5.0 mg/kg, 0.1-3.0 mg/kg, about 0.3-
3.0 mg/kg,
about 0.5-3.0 mg/kg, or about 1.0-3.0 mg/kg, such as about 0.1 mg/kg, about
0.3 mg/kg,
about 0.5 mg/kg, about 1.0 mg/kg, about 3.0 mg/kg, or about 5.0 mg/kg, of the
Col7
substance about one week after administration of the first loading dose; (iii)
administration of
a third loading dose of about 0.1-5.0 mg/kg, about 0.3-5.0 mg/kg, about 0.5-
5.0 mg/kg, about
1.0-5.0 mg/kg, about 0.1-3.0 mg/kg, about 0.3-3.0 mg/kg, about 0.5-3.0 mg/kg,
or about 1.0-
3.0 mg/kg, such as about 0.1 mg/kg, about 0.3 mg/kg, about 0.5 mg/kg, about
1.0 mg/kg,
about 3.0 mg/kg, or about 5.0 mg/kg, of the Col7 substance on the third week
of the
treatment; and optionally (iv) administration of a fourth loading dose of
about 0.1-5.0 mg/kg,
about 0.3-5.0 mg/kg, about 0.5-5.0 mg/kg, about 1.0-5.0 mg/kg, about 0.1-3.0
mg/kg, about
0.3-3.0 mg/kg, about 0.5-3.0 mg/kg, or about 1.0-3.0 mg/kg, such as about 0.1
mg/kg, about
0.3 mg/kg, about 0.5 mg/kg, about 1.0 mg/kg, about 3.0 mg/kg, or about 5.0
mg/kg, of the
Col7 substance on the fourth week of the treatment. In some embodiments, at
least one of the
first loading dose, second loading dose, third loading dose, and optional
fourth loading dose
differs from the other three. In some embodiments, the first loading dose,
second loading
dose, third loading dose, and optional fourth loading dose are the same. In
some
embodiments, the first loading dose is about 3.0 mg/kg. In some embodiments,
the second
loading dose is about 3.0 mg/kg. In some embodiments, the third loading dose
is about 3.0
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mg/kg. In some embodiments, the fourth loading dose is about 3.0 mg/kg. In
some
embodiments, the first loading dose, second loading dose, third loading dose,
and optional
fourth loading dose are each 3.0 mg/kg. In some embodiments, the second dosing
regimen
(maintenance phase) is performed after completion of the first dosing regimen
(loading
phase). In some embodiments, the second dosing regimen is performed
immediately after
completion of the first dosing regimen (e.g., after administration of the last
dose of the first
dosing regimen and corresponding dosing interval). In some embodiments, a dose
holiday is
used between the first dosing regimen and the second dosing regimen. In some
embodiments, the second dosing regimen comprises administration of a dose of
the Col7
substance daily, twice daily, weekly, every other week, every three weeks,
every four weeks,
every month, every two months, every three months, every four months, every
five months,
every six months, or every year. In some embodiments, the second dosing
regimen comprises
administration of about 0.1-5.0 mg/kg, about 0.3-5.0 mg/kg, about 0.5-5.0
mg/kg, about 1.0-
5.0 mg/kg, about 0.1-3.0 mg/kg, about 0.3-3.0 mg/kg, about 0.5-3.0 mg/kg, or
about 1.0-3.0
mg/kg, such as about 0.1 mg/kg, about 0.3 mg/kg, about 0.5 mg/kg, about 1.0
mg/kg, about
3.0 mg/kg, or about 5.0 mg/kg, of the Col7 substance. In some embodiments, the
second
dosing regimen comprises administration of about 3.0 mg/kg of the Col7
substance. In some
embodiments, the duration of the second dosing regimen is such that the
subject receives the
maintenance dose for more than one year, or more than five years, or more than
ten years, or
for the life of the subject.
[0143] In some embodiments, a method of treating a skin disorder
(e.g., DEB, such as
RDEB or DDEB), or ameliorating, alleviating, reducing, improving, delaying
onset of,
delaying progression of, eliminating, and/or curing a symptom or complication
of a skin
disorder such as DEB, in a subject (e.g., human subject) in need thereof
comprises
administering a Col7 substance (e.g., rhCol7 substance) according to a first
dosing regimen
and a second dosing regimen, wherein: i) the first dosing regimen includes
administering a
first therapeutically effective amount of the substance according to a first
dosing interval; and
ii) the second dosing regimen includes administering a second therapeutically
effective
amount of the substance according to a second dosing interval, wherein: a) the
first dosing
regimen lasts at least one week, the first frequency is weekly, and the first
effective amount is
about 0.1-10 mg/kg; and b) the second dosing regimen lasts at least four
weeks, the second
frequency is every other week, and the second effective amount is about 0.1-10
mg/kg. In
some embodiments, administration according to the first dosing regimen is
performed prior to
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administration according to the second dosing regimen. In some embodiments,
administration according to the first dosing regimen is performed immediately
prior to
administration according to the second dosing regimen (e.g., as described
herein). In some
embodiments, there is no gap between the first dosing regimen and the second
dosing
regimen (e.g., the second dosing regimen commences after the last dose of the
first dosing
regimen has been administered and corresponding dosing interval elapsed). In
some
embodiments, there is a gap of at least one day, such as at least two days,
three days, four
days, five days, six days, one week, two weeks, or longer, between the first
dosing regimen
and the second dosing regimen. In some embodiments, the first dosing regimen
lasts four
weeks. In some embodiments, the second dosing regimen lasts at least seven
weeks. In some
embodiments, the second dosing regimen comprises administering the Co17
substance to the
subject over the lifetime of the subject. In some embodiments, the first
effective amount and
the second effective amount are the same. In some embodiments, the first
effective amount is
about 0.1-5.0 mg/kg, about 0.3-5.0 mg/kg, about 0.5-5.0 mg/kg, about 1.0-5.0
mg/kg, about
0.1-3.0 mg/kg, about 0.3-3.0 mg/kg, about 0.5-3.0 mg/kg, or about 1.0-3.0
mg/kg, such as
about 0.1 mg/kg, about 0.3 mg/kg, about 0.5 mg/kg, about 1.0 mg/kg, about 3.0
mg/kg, or
about 5.0 mg/kg. In some embodiments, the first effective amount is 0.3 mg/kg
or 3.0 mg/kg.
In some embodiments, the second effective amount is about 0.1-5.0 mg/kg, about
0.3-5.0
mg/kg, about 0.5-5.0 mg/kg, about 1.0-5.0 mg/kg, about 0.1-3.0 mg/kg, about
0.3-3.0 mg/kg,
about 0.5-3.0 mg/kg, or about 1.0-3.0 mg/kg, such as about 0.1 mg/kg, about
0.3 mg/kg,
about 0.5 mg/kg, about 1.0 mg/kg, about 3.0 mg/kg, or about 5.0 mg/kg. In some
embodiments, the second effective amount is 0.3 mg/kg or 3.0 mg/kg. In some
embodiments,
the first effective amount and the second effective amount are the same. In
some
embodiments, the first effective amount and the second effective amount are
both 3.0 mg/kg.
In some embodiments, the subject has RDEB. In some embodiments, one or more
parameters of the second dosing regimen (e.g., duration, second frequency,
second effective
amount) is determined at least in part based on assessment of one or more
clinical parameters
of the subject during or after completion of the first dosing regimen.
Assessment of treatment efficacy
[0144] As discussed herein, a treatment regimen may be personalized as to the
dose
frequency, dosage, and duration time according to the subject's response, side
effect, and
treatment efficacy. In some embodiments, the subject being treated is
evaluated and assessed
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for treatment efficacy (e.g., between a first dosing regimen and a second
dosing regimen);
such assessments may be used to individualize the treatment schedule.
[0145] DEB patients may have different degrees of disease severity
by skin involvement
(e.g., mild, moderate, or severe) based on the percentage of body surface area
(BSA)
involvement represented by active and chronic wounds and supported by, e.g.,
the
classification system described by Fine et al. (J Am Acad Dermatol, 2008,
58(6): 931-502),
the contents of which are incorporated by reference herein in their entirety.
The changes from
a patient's baseline (pre-treatment measurement) may be assessed during and/or
following
the rhCol7 protein therapy. In some examples, one or more target wounds are
selected for
treatment efficacy assessment. A wound targeted for assessment may be about 3-
100 cm2 in
size. The wounds may be evaluated with images obtained using medical
photography and/or
evaluation by a physician. Each wound may be assessed individually one or more
times, such
as at each dose after the initial dose of the Col7 substance. An assessment of
a wound may
use a 7-point scale for changes from Baseline (Table 1).
Table 1: Wound specific 7-point scale
Score Definition
1 Very much improved
2 Much improved
3 Minimally improved
4 No change
Minimally worse
6 Much worse
7 Very much worse
[0146] Skin wounds may also be evaluated using imaging
methodologies for quantitative
wound surface area (WSA), including whole-body and wound-based medical
imaging. In
some embodiments, the WSA may be measured as the primary parameter of the
treatment. As
used herein, WSA is defined as the percentage of the wound affected body
surface area
(BSA), a calculated measure of WSA divided by estimated BSA. WSA is defined
relative to
the patient population, by wound boundaries, and other aspects of severity of
wound. The
wounds may include acute wounds such as blisters, erosions, and crusted
erosions, as well as
chronic wounds. The WSA methods may be based on the rule of nines body regions
by
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Wallace (The Lancet,1951), the contents of which are incorporated herein by
reference in
their entirety, and/or based on the Psoriasis Area and Severity Index (PAST)
(Berth-Jones et
al., 2006; Langley, 2004). In some examples, the WSA may be measured by wound-
based
quantitative medical imaging with a handheld 3-dimentional camera.
[0147] In addition, a Global Assessment (GA) may be used as the
basis for clinical
assessment of the average overall severity of the wounds (Table 2).
Table 2: Global Assessment (GA)
Score Definition
No blisters, no erosions, minimal erythema and/or pigmentary
0=c1car
changes may be present
2 or fewer small blisters, faint signs of erosion may be present, barely
1=near clear
perceptible evidence of crusting, slight erythema
predominantly small and some medium blisters, minimal erosions,
2=mild
clear crusting, definite well-defined erythema
Mix of small and medium blisters, definite erosions, limited areas of
3= moderate
crusting, marked erythema
Mix of medium and large blisters, marked erosions, ulcerations may
4= severe
be present, marked and extensive crusting, intense erythema
[0148] During the course of a rCol7 replacement treatment (e.g., as
described herein), a
biopsy (e.g., punch skin biopsy) may be obtained at intervals, e.g., between
doses at during a
first dosing regimen (e.g., loading dosing phase) and/or second dosing regimen
(e.g.,
maintenance dosing phase), for directly measuring deposition of Col7 protein
into the DEJ of
the skin. The measurement can be done with immunofluorescence (DIE) staining
using anti-
Col7 antibodies. Immunoelectron microscopy (IEM) may also be performed to
assess
whether functional anchoring fibrils form in the tissue, and if the dermal-
epidermal
separation is reversed after the rhCol7 protein therapy.
[0149] In some embodiments, suction blister time (SBT) can be
determined to measure the
epidermal-dermal skin adherence, thereby assessing treatment efficacy and for
modifying
dosing regimen. As the RDEB skin blisters more easily than the healthy skin.
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[0150] In some embodiments, other complications and symptoms
relevant to DEB patient
populations are assessed, such as gastrointestinal related clinical
manifestations, and other
non-skin systemic manifestations, dysphagia (difficulty in swallowing), eye
erosion, nail
dystrophy, alopecia, and mitten deformities of the hands and feet and skin
cancer (see, e.g.,
Fine et al., J Am Acad Dermatol. 2014, 70:1103-1126). In other embodiments, a
global
assessment for dermatologic conditions that involve multiple areas of skin
involvement such
as psoriasis or atopic dermatitis is performed.
[0151] In some embodiments, the subject undergoing rCol7
replacement therapy is
assessed for overall activity of life using the Epidermolysis Bullosa Disease
Activity and
Scarring Index (EBDAS1) activity subscales, an instrument used to characterize
disease
severity and response. The subject, before the treatment, may be assessed, and
given a
baseline status for the overall severity of the patient's EB (e.g., a Global
Impression of
Severity, GIS) considering the cutaneous and systemic manifestations of DEB. A
GIS may
be, for example, not assessed, mild, moderate, or severe. After the treatment
starts, the
subject may be assessed after each dosing, and given an overall status change
considering the
cutaneous and systemic manifestations of DEB. The status change is referred to
as Global
Impression of Change (GIC). The change score is from 1 to 7 as indicated in
Table 1.
Combined treatment
[0152] In one aspect, the Col7 substance (e.g., rhCol7 substance)
may be used in
combination with other one or more other treatments for DEB, such as one or
more
treatments for skin wounds associated with DEB such as RDEB in a subject.
[0153] Other treatments that may be used in combination with the
systemic rhCol7
replacement therapy provided herein may include, but are not limited to,
topical therapies
(e.g., topical cream comprising Col7 as described in U.S. patent application
publication No.
2015/313967 or topical therapy comprising Coenzyme Q10 as described in US
patent
application publication No. 2018/369164, the contents of each of which are
incorporated
herein by reference in their entirety); cell-based delivery of Col7 (e.g.,
skin keratinocytes
mediated Col7 delivery in the PCT publication No. W02017/120147, the contents
of which
are incorporated herein by reference in their entirety); viral vector mediated
delivery of Col7
(e.g., herpes simplex virus (HSV) mediated delivery of Col7 in the PCT
publication No.
W02017/176336. the contents of which are incorporated herein by reference in
their
entirety); aminoglycoside agents that induce read-through of COL7A1 premature
termination
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codon (PTC) mutations (e.g., gentamicin and amlexanox, as described in, e.g.,
Atanasova et
al., J Invest Dermatol. 2017, 137(9):1842-1849); RNA editing therapy (e.g.,
Bremer et al..
Mol Ther Nucleic Acids. 2016; 5:e379); and/or physical interventions including
bandages,
wraps, sutures, stitches, braces, patches, sealing films and glues (e.g.,
bandages initially
applied as liquids), staples, clips, and the like.
[0154] In some embodiments, the systemic rhCol7 protein therapy is
used in combination
of an anti-infection agent (e.g., an antibiotic), an antioxidant (e.g.,
Vitamin B3, Vitamin A, or
Vitamin C), a growth factor (e.g.. FGFP), anti-inflammatory agents, pain
relievers, and/or
another skin healing agent, such as an antibiotic agent, antiseptic, hydrogcl,
hydrocolloid,
alginate, petroleum jelly, aloe vera, cleansing agent, irrigant, moisturizer,
or physical
intervention (e.g., as described herein).
EQUIVALENTS AND SCOPE
[0155] Those skilled in the art will recognize or be able to
ascertain using no more than
routine experimentation, many equivalents to the specific embodiments in
accordance with
the disclosure described herein. The scope of the present disclosure is not
intended to be
limited to the above Description, but rather is as set forth in the appended
claims.
[0156] In the claims, articles such as "a," "an," and "the" may
mean one or more than one
unless indicated to the contrary or otherwise evident from the context. Claims
or descriptions
that include "or" between one or more members of a group are considered
satisfied if one,
more than one, or all of the group members are present in, employed in, or
otherwise relevant
to a given product or process unless indicated to the contrary or otherwise
evident from the
context. The disclosure includes embodiments in which exactly one member of
the group is
present in, employed in, or otherwise relevant to a given product or process.
The disclosure
includes embodiments in which more than one, or the entire group members are
present in,
employed in, or otherwise relevant to a given product or process.
[0157] It is also noted that the term "comprising" is intended to
be open and permits but
does not require the inclusion of additional elements or steps. When the term
"comprising" is
used herein, the term "consisting of" is thus also encompassed and disclosed.
[0158] Where ranges are given, endpoints are included. Furthermore,
it is to be
understood that unless otherwise indicated or otherwise evident from the
context and
understanding of one of ordinary skill in the art, values that are expressed
as ranges can
assume any specific value or subrange within the stated ranges in different
embodiments of
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the disclosure, to the tenth of the unit of the lower limit of the range,
unless the context
clearly dictates otherwise.
[0159] In addition, it is to be understood that any particular
embodiment of the present
disclosure that falls within the prior art may be explicitly excluded from any
one or more of
the claims. Since such embodiments are deemed to be known to one of ordinary
skill in the
art, they may be excluded even if the exclusion is not set forth explicitly
herein. Any
particular embodiment of the compositions of the disclosure (e.g., any
antibiotic, therapeutic
or active ingredient; any method of production; any method of use; etc.) can
be excluded
from any one or more claims, for any reason, whether or not related to the
existence of prior
art.
[0160] It is to be understood that the words which have been used
are words of description
rather than limitation, and that changes may be made within the purview of the
appended
claims without departing from the true scope and spirit of the disclosure in
its broader
aspects.
[0161] While the present disclosure has been described at some
length and with some
particularity with respect to the several described embodiments, it is not
intended that it
should be limited to any such particulars or embodiments or any particular
embodiment, but
it is to be construed with references to the appended claims so as to provide
the broadest
possible interpretation of such claims in view of the prior art and,
therefore, to effectively
encompass the intended scope of the disclosure.
EXAMPLES
Example 1: In vitro pharmacodynamic studies
Platelet aggregation
[0162] The platelet aggregation activity and hemolytic activity
might be caused by the
homology of the N-terminal non-collagenous domain 1 (NC-1) of C7 alpha-chains
to von
Willebrand Factor (vWF) (Leineweber S, et al., FEBS Lett. 2011; 585(12):1748-
52).
[0163] In this study, the rhCol7 substance was tested for the
potential of platelet
aggregation in vitro in monkey and human blood samples up to a concentration
of 200
micrograms per milliliter (Rg/mL). Citrated whole blood samples were collected
from 6
human subjects and 6 Cynomolgus monkeys. Platelet rich plasma (PRP) samples
were
prepared and standardized to reach a platelet concentration between 244 x 103
and 267 x 103
cells per microliter (cells/pL) in human PRP and between 210 x 103 and 255 x
103 cells/pL in
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monkey PRP. Samples were loaded in the aggregometer in duplicate in pre-heated
cuvette at
37 C for 2 minutes, before spiking with 0.9% NaC1 (negative control); ReoPro
(inhibition
control); collagen (positive control); reference item (buffer); the rhCol7
composition at 2, 50,
100 and 200 mg/mL final concentration in human PRP; or the rhCol7 composition
at 2. 25, 62
and 126 jig/mL final concentration in monkey PRP. Immediately after being
spiked, the
platelet aggregation was monitored for 6 minutes. The results indicate that no
activation
effect was observed following in vitro treatment of human PRP with 2, 50, 100
and 200
lag/mL rhCol7. rhCol7 also displayed no biologically significant activation
effect following in
vitro treatment of monkey PRP with 2, 25, 62 and 126 pg/mL rhCol7. Although a
slight dose-
dependent increase was observed in monkey PRP, this slight increase was not
biologically
significant as compared to the collagen positive control.
[0164] There is no biologically significant increase in platelet
activation and aggregation
observed in monkey platelet rich plasma (PRP) as compared to the collagen
positive control.
No platelet activation effect was observed following in vitro treatment of
human PRP with
rhCol7 substance up to 200 pg/mL.
Hernolysis
[0165] The hemolytic potential of rhCol7 compositions was
investigated in vitro in blood
from rat, cynomolgus monkey, and human. rhCol7 substance formulated in the
vehicle (10
mM sodium phosphate, 5 mM sodium citrate, 70 mM NaCl, 100 mM L-arginine, 1.7%
sucrose, and 0.05% (v/v) polysorbate 20 at pH 7.2) was tested in rat whole
blood samples
from Crl:CD(SD) rats at concentrations of 40, 95, and 185 ig/mL; in non-human
primate
(cynomolgus monkey) whole blood at concentrations of 25, 62.5, and 125 tig/mL;
and in
human whole blood at concentrations of 50, 100. and 200 pg/mL. Three
concurrent control
tests were performed using the control vehicle; positive (deionized water) and
negative (0.9%
sodium chloride for injection) control articles in each type of blood were
tested. The blood
and treatment volumes per sample were each 0.5 mL (1.0 mL total) for all tests
and were
conducted using 5 replicates for each test. Each incubation was carried out at
approximately
37 C for approximately 60 minutes. The percentage hemolysis for each sample
was
calculated according to the formula modified from Makroo et al. (Asian Journal
of
Transfusion Science 2011, 5, 15-17).
[0166] In rat, non-human primate, and human blood, hemolysis was
detected in the
positive control group, with mean percent hemolysis values ranging from 34.6%
to 37.0%.
At all exposure levels in each of the 3 blood matrices, no hemolysis was
detected. Mean
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percent hemolysis values for the treated groups ranged from 0.3% to 0.5%. No
hemolysis was
detected in the negative or vehicle control groups. Mean percent hemolysis
values ranged
from 0.3% to 1.2% for the negative control and from 0.3% to 0.6% for the
vehicle control.
Based on these results, no hemolysis was detected at concentrations up to
rhCol7 185 ilg/mL
in rat blood, concentrations up to rhCol7 125 1.1g/mL in non-human primate
blood, and
concentrations up to rhCol7 200 pg/mL human blood.
Example 2: Preclinical efficacy studies of rhCo17 compositions in a mouse DEB
model
(in vivo primary pharmacodyrtamic studies)
[0167]
The mouse model of DEB (Col7a1-/) with a targeted inactivation of the
COL7A1
gene (Heinonen et al., J Cell S'ci. 1999, 112: 3641-3648) have no detectable
Col7 at the
dermal-epidermal BMZ, completely lack anchoring fibrils, and are born with
extensive
cutaneous blisters on their ventral surface and hemorrhagic blisters on their
paws and neck,
with mortality typically observed within the first week of life. This DEB
mouse model
(Col7a1j-) results in severe blistering that mimics the clinical,
histological, and ultrastructural
presentation of severe human recessive DEB (RDEB). Using this mouse model,
nonclinical
efficacy studies were performed for dose-dependent response and efficacy after
intravenous
administration of the rhCol7 drug product, for studying formation of anchoring
fibrils,
distribution and localization of rhCol7, and histological and survival effects
after rhCol7
intravenous dosing. The study design is summarized in Table 3. In Table 3,
doses of 16 pig,
28 jag and 40 jig equate to approximately 8, 14 and 20 mg/kg, respectively,
based on 2 g body
weight.
Table 3: Experimental design of primary pharmacodynamic studies in DEB mice
Method of Dose and
Experimental design
Measurements
administration concentration
Vehicle control PBS
Single dose on post- (phosphate buffered
neonatal day 2/3 (PND saline, 0.5mM
Distribution,
i.v. bolus
2/3) DEB mice EDTA), 401iL,
histological and
Study 1 (superficial
n=27 (rhCo17) rhCol7 (Batch 1) survival
temporal vein)
n=20 (FB-Col7 (16ttg; 401iL),
endpoints
n=13 (control vehicle) FB-rCol7 (16ag;
40 L)
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Method of Dose and
Experimental design
Measurements
administration concentration
Daily dose for 7 days on Control
PBS (40gL),
PND 2/3 DEB mice rhCol7 (Batch 1)
i.d. injection Formation of
Study 2 n=3 (control vehicle) (16pg; 40 L),
(dorsum)
anchoring fibrils
n=5 (FB-Co17) FB-rCol7 (16 g;
n=6 (rhCo17) 4011E)
Control PBS (40 L),
Single dose on PND 2/3
rhCol7 (Batch 1) (28
DEB mice
i.v. bolus ug; 70 L),
11=3 (control vehicle)
Formation of
Study 3 (superficial rhCol7 (Batch
1)
n=3 (FB-Co17) anchoring fibrils
temporal vein) (40 g; 100 L)
n=7 (rhCol7; 40 g)
FB-rCol7 (40 g;
n=3 (rhCol7; 28 g)
100pL)
Vehicle Control PBS
(40 L);
Vehicle 2 (137 mM
sodium chloride, 2.7
mM potassium
chloride, 10 mM
i.v. bolus
Distribution,
Single dose on PND 2/3
phosphate, 0.5 mM
Study 4 (superficial
histological
DEB mice EDTA, pH 7.1)
temporal vein) improvement
(40 L);
rhCol7: 2.5mg/kg
(.5 g/40 L); or 8
mg/kg (16 g/40 L),
or 14mg/kg (28ug /
70 1_,) (Batch 1)
Repeat-dosing on Days Vehicle
Control PBS
1, 3 and 5 on PND 2/3 (40 L);
DEB mice iv. bolu s Vehicle 2 (40 tiL);
Distribution,
Study 5 n=3 (control) (superficial
rhCol7: 0.5mg/kg histological
n=5 (rhCo17, 0.5mg/kg) temporal vein) (40 L); or lmg/kg improvement
n=6 (rhCo17, lmg/kg) (40 L); or 5mg/kg
n=6 (rhCol7, 5mg/kg) (70 L) (Batch 2)
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Method of Dose and
Experimental design
Measurements
administration concentration
Single dose on PND 2/3
DEB mice
n=11 (control) Vehicle Control PBS
Distribution,
i.v. bolus
n=19 (rhCol7, 16 g, (40 L);
histological and
Study 6 (superficial
40pL) (Batch 2) rhCol7 (16p g; 401u L) survival
temporal vein)
n=14 (rhCol7, 16tig, (Batches 1 and 2)
endpoints
40t.tL) (Batch 1)
Vehicle (10 mM
sodium phosphate, 5
Single dose on PND 2/3
mM sodium citrate,
DEB mice
70 mM sodium
n=10 (control)
Distribution,
i.v. bolus chloride, 100
n=26 (rhCo17_Batch 3,
histological and
Study 7 (superficial arginine, 50 mM
16tig, 40 L)
survival
temporal vein) sucrose, 0.05%
n=26 (rhCo17_Batch 4,
endpoints
polysorbate 20, pH
16tig, 40 L)
7.1) (40 L)
rhCol7 (Batches 3
and 4) (16 g; 40 .L)
[0168]
In Studies 1-3, neonatal DEB Col7a11- mice were administered a single i.v.
bolus
of phosphate buffered saline (PBS) and formulation vehicle control, rhCol7
compositions
(Batches 1, 2, and 3) or reference Col7 (wild type Col7 derived from
Fibroblasts; FB-Col7)
via the superficial temporal vein. The formation of anchoring fibrils was
evaluated after a
single dose administration of rhCo17 (i.v.; 16 jig (8 mg/kg)) (Study 3) and
after once daily
intradermal (i.d.) dosing for 7 days (16 pg (8 mg/kg)) (Study 2).
[0169] Distribution of rhCol7 and histological and survival
endpoints were evaluated after
single dose administration of rhCo17 (28 pg (14 mg/kg), 40 jig (20mg/kg))
(Studies 1, 6 and
7). Indirect immunofluorescence (IF) staining of tongue tissues obtained from
DEB Col7a1-/-
mice following i.v. administration with rhCol7 composition, FB-rCol7 or
control PBS.
[0170]
The results demonstrated that the rhCol7 composition was detected at the
dermal-
epidermal BMZ in tongue and skin in 3 out of 5 rhCol7 composition-dosed and 2
out of 6
FB-rCo17-dosed mice surviving more than 90 days. Both rhCol7 composition and
FB-rCol7
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distributed to the proper location within the dermal-epidermal junction. The
rhCol7
composition was also detected in the esophagus of 2 mice surviving to 18 and
90 days. The
results suggest that both rhCol7 and reference collagen 7 (FB-rCol7)
distributed to the
dermal-epidermal BMZ in tongue and skin following a single i.v. dose (16 jag
(8 mg/kg)),
while no detectable rhCol7 was found in vehicle control DEB mice.
[0171] Transmission electron microscopy of the tongue revealed
formation of anchoring
fibrils directly beneath the lamina densa of the dermal-epidermal BMZ
following a single i.v.
dose (28 or 40 lag) of rhCol7 composition and FB-rCol7, while no anchoring
fibrils were
present in vehicle control mice. The rhCol7 composition administered i.d. (16
jag) for 7 days
into dorsum skin, demonstrated formation of cross-banded anchoring fibrils
protruding
perpendicularly from the dermal-epidermal BMZ (Study 2).
[0172] Single dose intravenous administration of rhCo17 composition
or FB-rCol7 to
Col7a1-/- DEB mice corrected the separation between the epidermis and dermis
in tongue
tissue. In contrast, PBS injected mice showed pronounced separation of the
epidermis from
the dermis. The proportion of mice with complete closure between the epidermis
and dermis
in tongue was 48% (12/25), 67% (12/18), and 0% (0/12) for rhCo17 composition,
FB-rCol7,
and vehicle control, respectively. The proportion of complete closure was
statistically
different in rhCol7 composition and FB-rCol7 treated mice compared to vehicle
control mice.
[0173] Studies have demonstrated that i.v. administration of rhCol7
will restore functional
Col7 to the dermal-epidermal BMZ. This is expected to promote the assembly of
normal
anchoring fibrils, providing stability to dermal-epidermal adhesion at the
lamina densa/upper
papillary dermis interface, and correct blistering abnormalities and
complications in patients
with DEB. rhCol7 formed anchoring fibrils, and corrected separation of the
epidermis from
the dermis in DEB mice.
[0174] A single i.v. dose (16 i_tg (8 mg/kg)) of rhCol7 composition
or FB-rCol7 resulted in
a statistically significant improvement in survival compared to vehicle
controls. The median
(intcrquartilerange) survival time was 4, 8, and 16.5 days for Col7a1-/- mice
administered
vehicle control, rhCol7 composition, and FB-rCol7, respectively. The
proportion of mice
surviving beyond 30 days was 0% (0/13), 19% (5/27), and 35% (7/20)
respectively for mice
administered vehicle control, rhCo17 composition, and FB-rCol7, respectively.
[0175] A separate single dose response (5, 16 or 28 jig; equivalent
to approximately 2.5, 8
and 14mg/kg, respectively) and repeat dose response (dosing on Days 1, 3 and 5
at 0.5, 1 and
mg/kg) study in the same mouse model of DEB was conducted (Studies 4 and 5)
(Table 3).
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Intravenous administration of the rhCo17 composition resulted in a dose-
dependent deposition
at the dermal-epidermal BMZ in target tissues following a single dose of 2.5,
8 and 14 mg/kg
(tissues collected at death) and repeat-dose administration at 0.5, 1 and 5
mg/kg on Days 1, 3
and 5 (tissues collected on Day 6) (FIG. 1).
[0176] Semi-quantification of the IF signal from the repeat-
administration dose-response
study also showed that rhCol7 distribution to the dermal-epidermal junction
was dose
dependent;
[0177] the minimum efficacious dose was considered to be 5 mg/kg
based on distribution
to the dermal epidermal BMZ in both tongue and skin. A single dose of the
rhCol7
composition resulted in a dose dependent correction of dermal-epidermal
separation in
tongue.
[0178] A dose dependent correction of dermal-epidermal separation
in neonatal Col7a1-/-
mice was also observed following a single intravenous administration of rhCol7
composition
(as demonstrated in FIG. 2A). Quantification of the number of mice exhibiting
complete
closure of dermal-epidermal separation is shown in FIG. 2B.
[0179] In studies 6 and 7 for efficacy of rhCol7 compositions,
similar distribution results
were observed. Following a single dose (8nag/kg (16 g)) by intravenous
administration,
rhCol7 was distributed to the deimal-epidermal BMZ in the tongue in all rhCol7
treated mice,
as well as to the skin obtained from the abdomen, back, and front leg in
evaluated roCol7
treated mice. rhCol7 was not detected in any vehicle control mice.
[0180] Administration of rhCol7 compositions (Batch 1 and 2)
resulted in correction of
dermal-epidermal separation in Col7a1-/- mice as well. The proportion of mice
with
complete closure between the epidermis and dermis in tongue was 79% (15/19),
71% (10/14),
and 27% (3/11) for mice administered rhCol7 composition (Batch 1), rhCol7
composition
(Batch 2) and vehicle control, respectively in Study 6. The proportion of mice
with reversal
of dermal-epidermal separation was significantly higher in rhCol7 compositions
treatment
groups compared to vehicle control. In contrast, the proportion of mice with
reversal of
dermal-epidermal separation was similar between both treatment groups. A
statistically
significant improvement in survival in rhCol7 dosed groups was observed
compared to
vehicle controls. The median (interquartile-range) survival time was 3, 4.5,
and 11 days for
mice administered vehicle control, rhCol7 (Batch 1) and rhCol7 (Batch 2),
respectively.
[0181] Similar results are observed in study 7. For example, rhCol7
compositions (both
batches) distributed to the dermal-epidermal BMZ in tongue and front leg skin,
while rhCol7
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was not detected in ant vehicle control mice. Correction of dermal-epidermal
separation was
observed in rhCo17 compositions dosed animals. The proportion of mice with
complete
closure of dermal-epidermal separation was higher in rhCol7 composition
treated mice (46%
(12/26) (Batch 3). and 58% (15/26) (Batch 4)) than vehicle control (10%
(1/10). A
statistically significant improvement in survival of PTR-01 treated animals
compared to
vehicle controls was observed. The median survival time was 2.5, 9, and 14
days for Col7a1-
I- mice administered vehicle control, rhCol7 (Batch 3) and rhCol7 (Batch 4),
respectively. A
correlation between histology and survival is observed.
[0182] These results and observations suggest that rhCol7
compositions by a single
intravenous administration can distribute and localize to the proper location
within the
dermal-epidermal BMZ, form anchoring fibrils, correct dermal-epidermal
separation, and
result in a statistically significant improvement in survival compared to
vehicle controls.
Results are similar for mice administered recombinant human rhCo17 purified
from human
dermal fibroblasts (FB-rhC7), the positive control.
[0183] The dose-dependent response is observed both in a dose
escalation study utilizing
single i.v. administration of rhCol7 composition, and in a dose-dependent
study with repeat
administration of rhCol7 compositions; the responses include dose-dependent
distribution of
rhCo17 compositions to the dermal-epidermal BMZ in target tissues and a dose-
dependent
reversal of dermal-epidermal separation. The observation suggests a minimum
efficacious
dose is 5 mg/kg based on distribution to the dermal-epidermal BMZ in both
tongue and skin.
Example 3: In vivo pharmacokinetics and toxicokinetics of rhCol7 compositions
[0184] Pharmacokinetic (PK) / toxicokinetic (TK) characteristics of
rhCol7 have been
assessed in mice, rats, and monkeys, including single dose and 28-days weekly
repeat dose
studies by the intravenous (i.v.) route. The characterization includes PK/TK
evaluations in
repeat-dose studies in rats and monkeys, tissue distribution using
quantitative whole-body
autoradiography (QWB A) in rats and ADA analysis in the repeated dose
toxicity.
Absorption, distribution, and excretion of rhCol7 compositions were tested in
rat, monkey,
and dog. The studies for these purposes are listed in Table 4.
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Table 4: Pre-clinical pharmacokinetic studies with rhCol7 compositions
Method of Dose and
Experimental system Measurements
administration concentration
Rat, Sprague-Dawley
rhCol7 (().5, 2
Study 8 (males only) single-dose; i.v.
Absorption
and 5 mg/kg)
(n=12/rhCol7group)
Monkey, Cynomolgus
rhCol7 (0.5, 2
Study 9 (females only) single-dose; i.v.
Absorption
and 5 mg/kg)
(n=3/rhCol7group)
Rat, Sprague-Dawley
rhCol7 (2, 5
(n=12 2mg/kg rhCol7,
Study 5 doses/28 days, and 10 mg/kg)
n=12, 5mg/kg rhCol7 Absorption
i.v. control
n=12, 10mg/kg rhCol7
vehicle
n=8 control)
Monkey, Cynomolgus
(n=8, 2mg/kg rhCol7
Study 5 doses/28 days, rhCol7 (2, 5
n=14, 5mg/kg rhCol7 Absorption
11 i.v. and 10mg/kg)
11=14, 10mg/kg rhCol7
n=14 control)
Monkey, Cynomolgus
Study 5 doscs/28 days, rhCol7 (4 and
(n=12, 4mg/kg rhCo17 Absorption
12 i.v. 8 mg/kg)
n= 12, 8mg/kg rhCol7)
Study Mouse, Col7a1-/- (DEB Half-
life in tongue
i.v.
13 model)
and skin
Distribution in
Mouse, tamoxifcn- 2 doses at 20
Study tongue,
esophagus
inducible C7 knockout minutes
14 and skin
(intact and
(DEB model) intervals; i.v.
wound)
Tissue distribution;
Study Rat, Sprague-Dawley rhCol7 (2
single-dose; i.v. and
excretion (urine
(n=3) mg/kg)
and feces)
Study
Distribution in skin
Dog, RDEB model single-dose; i.v.
16
and lip
Single dose-absorption in Rats and Monkeys
[0185] After single i.v. slow push (1-3 minutes) administration of
0.5, 2 and 5 mg/kg to
male Sprague-Dawley Crl: CD rats (12 males/group) (study 8). Blood samples
were collected
prior to dosing and at approximately 2, 5, 15, 30. and 45 minutes, 1, 2, 4, 8,
12, and 24 hours
after dose administration on Day 0. Serum samples were analyzed with
electrochemiluminescence (ECL). Exposure to rhCo17 composition increased with
the
increase in rhCol7 dose from 0.5 to 5 mg/kg in a greater than dose-
proportional manner in
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terms of area under the curve from time zero to infinity (AUCinf) and dose-
proportional in
terms of C.. However, the increase in exposure in terms of AUCinf was dose-
proportional
from 2 to 5mg/kg. A 10-fold increase in dose resulted in approximately 9- and
33-fold in
terms of Cma. and AUCinf, respectively. Peak serum concentrations of rhCol7
were observed
at the first sampling point (2 minutes) post-dose at all dose levels. Cl was
low ranging from
83.7 to 276 mL/h/kg, and the volume of distribution at steady state(V) was
small, ranging
from 17.1 to 33.1 mL/kg. The resulting terminal half-life (T1/2) was short,
ranging from 0.108
to 0.293 hour. Cl appeared to slightly decrease from 0.5 to 2 mg/kg and
remained similar at 2
and 5 mg/kg. At 5 mg/kg the maximum scrum concentration (C.) was 105,000 ng/mL
and
AUCo-24 was 59,800 ng*hr/mL.
[0186] Similarly, after single i.v. slow push (1-2 minutes)
administration of 0.5, 2, and 5
mg/kg rhCo17 at a dose volume of 10 mL/kg, to female Cynomolgus monkeys (3
fernales/group) (study 9). Blood samples were collected prior to dosing and at
approximately
2, 5, 15, 30, and 45 minutes and 1, 2, 4, 8, 12, and 24 hours after dose
administration on Day
0. Serum samples were analyzed with ECL. rhCol7 serum concentrations were
measurable in
at least 1 of 3 animals through 4-, 12-, and 24-hours post-dose at 0.5, 2, and
5 mg/kg.
respectively. Peak serum concentrations of rhCol7 were observed at the first
sampling point
(2 minutes) post-dose at all dose levels. Serum concentrations appeared to
decrease in a bi-
phasic manner. Exposure to rhCol7 increased with the increase in rhCol7 dose
from 0.5 to 5
mg/kg in a greater than dose-proportional manner in terms of AUCiLif and dose-
proportional
in terms of C.. The increase in exposure in terms of AUCint- was nearly dose-
proportional
from 2 to 5 mg/kg. Plasma clearance (Cl) was low, ranging from 43.7 to 163
mL/h/kg and Vss
was small, ranging from 32.2 to 51.9 mL/kg. The resulting t112 ranged from
0.347 to 5.59
hours. At 5 mg/kg the Cmax was 135,000 ng/naL and AUCo-24 was 116,000
ng*hr/mL.
Repeat dose- absorption in Rats and Monkeys
[0187] After repeated once weekly i.v. bolus injections of 2, 5 and
10 mg/kg /week (5
doses in total over a 28-day dosing period) at a dose volume of 10 mL/kg to
Sprague-Dawley
Crl: CD rats (n=12/dose) (study 10). A concurrent control group (n=8) received
the vehicle
on the same regimen. Blood samples were collected at approximately 5 and 15
minutes after
dose administration on Days 0 and 28 for the control group and prior to dosing
and at
approximately 5 and 15 minutes and approximately 1, 2, 4, 8, 12, and 24 hours
after dose
administration on Days 0 and 28. Serum samples were analyzed with ECL.
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[0188] rhCol7 serum concentrations were below the level of
quantification (BLQ) in all
samples prior to dosing with rhCo17 compositions and in samples collected from
control
animals on Days 0 and 28. In general, exposures were similar on Day 0 and Day
28 for all
dose groups and accumulation of rhCol7 compositions was not observed after
once weekly
administration for 28 days. Accumulation ratios ranged from 0.516 to 1.27.
Clearance was
low (approximately 1.07 to 3.64 mL/nain/kg for combined male and female data)
and Vss was
small (approximately 34.9 to 94.4 mL/kg for combined male and female data)
which resulted
in a mean terminal t1/2 range of approximately 0.196 to 0.787 hours for
combined male and
female data. No gender difference was observed. The TK parameters of rhCol7
are
summarized in Table 5.
Table 5: Toxicokinetic parameters for rhCol7 compositions after intravenous
Bolus
administration in Sprague-Dawley Rats
2 5 10
Dose (mg/kg/day)
Male Female Male Female Male Female
PK Parameters Day 0
AUC 0-24
13,500 13,500 50,800 36,600
126,000 123,000
(ng*hr/mL)
AUC,õf (ng*hr/mL) 13,400 13,400 50,700 36,400
126,000 123,000
Cmax (ng/mL) 20,400 29,400 56,700 47,300 96,500
109,000
Cl (mL/h/kg) 2.48 2.49 1.64 2.29 1.32
1.36
Vss (mL/kg) 0.0407 0.0284 0.0497 0.0596 0.0686
0.0664
T1/2(hr) 0.214 0.147 0.297 0.256 0.628
0.362
Day 28
AUC 0_24 (ng*hr/mL) 11,800 6,970 64,500 24,700 160,000
151,000
AUC ( h , L) 11600 f ocig*_r, m 6,910
64,300 24,600 160,000 151,000
C., (ng/mL) 14,000 21,100 63,300 47,900
136,000 98,900
CI (mL/h/kg) 2.86 4.82 1.30 3.39 1.04
1.11
Võ (mL/kg) 0.0996 0.0492 0.0597 0.113 0.0654
0.0669
Tv2(hr) 0.349 0.260 0.462 0.395 0.794
0.777
[0189] Two studies were conducted in monkeys to investigate the
toxicokinetic profile of
rhCol7 compositions. In study 11, after repeated once weekly i.v. slow push (1-
2 minutes)
injections of 2, 5 and 10 mg/kg/week (5 doses in total over a 28-day dosing
period) at a dose
volume of 10 mL/kg to Cynomolgus monkeys. Blood samples were collected once
during
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acclimation, prior to first dosing, prior to dosing on day 28, and at
approximately 5 and 15
minutes and 1, 2, 8, 12, and 24 hours after dose administration on days 0 and
28. Serum
samples were analyzed with ECL. There were no measurable rhCo17 concentrations
in serum
samples collected from control group animals. In general, exposure to rhCo17
(AUC and
Cmax) was similar in males and females and there was no consistent gender
difference.
[0190] Following i.v. bolus administration of rhCol7 composition at
2 mg/kg/week,
rhCol7 serum concentrations were measurable from 0.083 hours post-dose through
2-, 4-, or
8-hours post-dose on both days. In the 5 and 10 mg/kg/week dose groups, rhCo17
serum
concentrations were measurable from 0.083 hours post-dose through 4-, 8-, 12-,
or 24-hours
post-dose on both days.
[0191] The accumulation ratios ranged from 0.738 to 1.50. Clearance
was low (<5
mL/min/kg) and Vss was small (<0.105 L/kg) which resulted in a relatively
short mean t1/2 that
ranged from 0.304 to 1.36 hours for combined male and female data. The male
and female
toxicokinetic parameters for rhCol7 are summarized in Table 6.
Table 6: Toxicokinetic parameters for rhCol7 compositions after intravenous
slow push
administration in monkeys
2 5 10
Dose (mg/kg/day)
Male Female Male Female Male
Female
PK Parameters Day 0
AUC0 24
21,500 29,800 157,000 120,000 415,000 439,000
(ng*hr/mL)
AUCllit (ng*hr/mL) 21,300 29,700 157,000 120,000
414,000 438,000
Crnax(ng/inL) 47,200 55,700 120.000 124,000 166,000 256,000
CI (mL/h/kg) 0.083 0.125 0.536 0.131 0.155
0.131
Võ (mL/kg) 1.56 1.19 0.576 1.07 0.449
0.410
Tv2(hr) 0.0384- 0.0338 0.0370 0.139 0.0489
0.0379
Day 28
AUG) 24
16,900 20,000 182,000 133,000 449,000 446,000
(ng*hr/mL)
AUCillf (ng*hr/mL) 16,700 19,700 181,000 132,000
449,000 446,000
Cinax (ng/mL) 27,800 38,400 126,000 108,000
197,000 213,000
Cl (mL/h/kg) 0.125 1.125 0.762 0.262 0.178
0.702
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Võ (mL/kg) 2.12 6.06 0.501 0.663 0.681 0.374
Tv2(hr) 0.0789 0.125 0.0308 0.0407
0.116 0.0383
[0192] In study 12, after repeated once weekly i.v. infusions (1
hour) of 4 and 8
mg/kg/week (5 doses in total over a 28-day dosing period) at an infusion rate
of 6.6 mL/kg/h
to Cynomolgus monkeys . Blood samples were collected prior to dosing, 30
minutes post
start of infusion and at 5 and 15 minutes, and 1, 2, 4, 8, 12, and 24 hours
post end of infusion.
Serum samples were analyzed with ECL. Over the dose range, exposure to rhCol7
(based on
AUCO-Tlast, AUCuat and Cmax values) on Days 1 and 29 generally increased dose-
dependently
and in slightly to moderately more than dose-proportional manner. There were
generally no
marked gender-related differences. The AUCs and Cmax accumulation ratios (Day
29/Day 1)
ranged from 0.9 to 1.7 indicating that rhCol7 does not accumulate when
administered once
weekly as i.v. infusion over a period of 1 hr/day to Cynomolgus monkeys for 4
weeks for a
total of 5 doses
[0193] The mean estimated t1/2ranged from 0.359 to 0.857 hours on
Day 1 and from 0.427
to 1.40 hours on Day 29. rhCol7 was cleared at a mean rate of 43.8 to 71.9
mL/hour/kg on
Day 1 and a mean rate of 27.1 to 54.4 mL/hour/kg on Day 29. The mean volume of
distribution during terminal phase (Vz) ranged from 31.0 to 52.4 mL/kg on Day
1 and from
31.3 to 47.8 mL/kg on Day 29, suggesting that rhCol7 is confined to a large
extent in the
circulating system. The TK parameters for rhCo17 are summarized in Table 7.
Table 7: Toxicokinetic parameters for rhCol7 after intravenous infusion in
monkeys
2 8
Dose (mg/kg/day)
Male Female Male Female
PK Parameters Day 1
AUG, Tlast (ng*hr/mL) 74,600 58,400 187,000 178,000
AUCitif (ng*hr/mL) 74,800 57,900 187,000
173,000
Cusax (ng/mL) 57,000 42,800 80,600
86,500
Tinax(hr) 1.11 1.11 1.08
1.14
Cl (mL/11/kg) 55.0 71.9 43.8
47.9
Vz (mL/kg) 31.0 36.8 52.4
42.1
Ti/2(hr) 0.391 0.359 0.857
0.628
PK Parameters Day 29
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AUC0 Tlast (ng*hr/mL) 88,000 76,700 326,000
181,000
AUCint (ng*hr/mL) 88,700 77,000 326,000
187,000
Cma, (ng/mL) 50,300 49,500 108,000 82,600
T.(hr) 1.22 1.12 1.17
1.33
Cl (mL/h/kg) 48.4 54.4 27.1 44.0
Vz (mL/kg) 42.3 31.3 47.8 36.8
Ti/2(hr) 0.631 0.427 1.40
0.612
Distribution
[0194] The half-life (Tu2) of rhCo17 compositions distributed in
tongue and skin was
determined in the DEB mouse model (Col7a 1 -/1) following a single i.v.
administration of
rhCol7 composition (8 mg/kg (16 jig) (Study 13). Tongue (n=25) and skin from
front and rear
paws (n=27) were collected and subjected to IF staining for rhCol7. Tissue
Ti/2 was estimated
with semi-quantitated IF signal at the dermal-epidermal BMZ specifically. The
tissue t1/2 in
tongue and skin obtained from paws was estimated to be 26.4 days and 32.6 days
respectively. The distribution of rhCol7 in tongue, esophagus and skin (intact
and wounded)
was further determined in the tamoxifen-inducible Col7 knockout DEB mouse
model
following i.v. administration (study 14). After a small wound was incised on
the back of the
C7-inducible knockout mice, two i.v. injections of 100 jig rhCol7 (8 mg/kg
(200 pg in total;
n=5) or vehicle (n=4) were administered. Two weeks after rhCol7 placebo
injection, the mice
were sacrificed and samples of tongue, esophagus and skin (intact and wounded)
were
collected for rhCol7 detection at the dermal-epidermal junction. rhCol7
distributed to the
dermal-epidermal BMZ in wounded skin of tamoxifen-inducible Co17 knockout mice
following i.v. administration. rhCol7 was not detected in tongue, esophagus or
unwounded
skin.
[0195] The distribution of [nj111=1,_
PTR-01 after a single i.v. administration to 8 Sprague
Dawley male rats at 2 mg/kg was assessed (Study 15). One animal/time point was
sacrificed
at 0.5-, 2-, 6-, 24-, 72-, 168-, 216-, and 336-hours post-dose. Following
administration of
EtitIn]-PTR-01 to rats the Cmax in blood and plasma were observed at 0.5 hours
post-dose.
The radioactivity concentrations in plasma were approximately 2-fold higher
than those in
blood. Levels of radioactivity in both matrices declined rapidly and were
approximately 5-
fold lower by 2 hours post-dose but were still detectable at 336 hours post-
dose. The highest
radioactivity concentrations and percentage of dose/g were observed in the
bone marrow,
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kidneys, liver, and spleen. The majority of the tissues had tissue:plasma
concentration ratios
>1 at the later time points indicating that drug-related radioactivity was
retained in tissues.
rhCol7 was detected in skin (unpigmented) at each time point including 336
hours post-dose;
the skin:plasma ratio at 336 h post-dose was 4.61.
[0196] The distribution of rhCol7 in the lip and skin (ear) was
determined in one female
RDEB dog following i.v. infusion of 4 mg/kg (study 16). The RDEB dog model is
a
spontaneous model with a homozygous glycine mutation in the collagenous domain
(G1906S). rhCol7 was detected faintly at the dermal-epidermal BMZ in skin
(ear) 3 days
post-dose. A very weak IF signal at the dermal-epidermal BMZ in skin was also
detected 25
days post-dose. In contrast, IF staining without the primary antibody
(immunoglobulin G
(-IgG) control) showed no staining at the dermal-epidermal BMZ. rhCol7 was
detected faintly
in the skin ear) but not in the lip. There were no changes in anchoring
fibrils and the suction
blister test in the one animal dosed.
Excretion
[0197] rhCol7 tissue distribution and excretion was studied in
[111Indium (In)]-rhCol7
treated rat (study 15). Sprague Dawley male rats was administered with
[111Indium (In)]-
rhCol7 by a single i.v. injection at a dose level of 2 mg/kg. Urine was
collected from animals
at 0-6 and 6-24 hours post-dose and thereafter at 24-hour intervals through
168 hours post-
dose. Feces were collected at 24-hour intervals through 168 hours post-dose.
Concentrations
of total radioactivity were determined in dose formulations using instant thin
layer
chromatography (iTLC) and solid scintillation counting (SSC), and quantitative
whole-body
autoradiography (QWBA). The autoradiographic images were analyzed to determine
tissue
concentrations of radioactivity.
[0198] Blood, plasma, urine, feces, and carcasses were analyzed by
SSC to determine
radioactivity concentrations. After i.v. administration of [win] -rhCol7 the
highest recovery
of drug-related radioactivity, accounting for a mean of 56.8% over the 0 to
168 hour
collection period, was found in the urine. Drug-related radioactivity was also
present in feces.
Approximately 30% of the administered dose remained in the carcass and total
recoveries
(urine, feces, and carcasses) were a mean of 95.9 1.04%.
[0199] In summary, there were no general gender differences in
systemic exposure as
measured by AUC and C.ax in either rats or monkeys. Elimination after i.v.
administration
was rapid, with 11/2 often less than half an hour in all species tested. In
both rodents and non-
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human primates rhCol7 half-life in plasma increased with dose. Exposure data
support
allometric scaling for human equivalent dose (HED) calculation. In the
tamoxifen-inducible
Col7 knockout mouse model rhCol7 distributed to the dermal-epidermal BMZ in
wounded
skin further confirming the specific homing of collagen VII. This is similar
to the tissue half-
life of endogenous murine Col7 in target tissues (skin, tongue and esophagus),
as estimated in
a tamoxifen-inducible Col7 knockout mouse model (Kuhl et al., J Invest
Dermatol., 2016,
136: 1116-1123). rhCol7 was widely distributed throughout the whole body of
the rat after
an i.v. administration. The highest amount of rhCo17 was observed in the bone
marrow,
kidneys, liver and spleen. In Sprague Dawley rats, levels of ['111n]-rhCol7 in
blood and
plasma declined rapidly and were approximately 5-fold lower by 2 hours post-
dose but were
still detectable at 336 hours post-dose after i.v. administration. rhCo17 was
detected faintly at
the dermal-epidermal BMZ in skin 3 days following a single i.v. infusion.
Example 4: Selection of patients prior to the rhCol7 drug treatment
[0200] Recessive dystrophic epidermolysis bullosa (RDEB) patients
with at least one
chronic (e.g., at least 6 weeks) lesion >2 cm2 are selected. Patients
diagnosed with RDEB
have a genetic analysis before enrollment for the rhCol7 protein treatment. A
blood sample is
collected from each patient for genotyping of Col7A1. Only patients showing a
mutation(s) in
the COL7A1 gene consistent with a recessive inheritance pattern, are enrolled.
Biopsy
samples are also obtained from patients for IF staining prior to the
enrollment. The patients
who have the presence of some but deficient Col7 staining at the deinial-
epidermal junction
(DEJ) by IF staining are selected.
Example 5: Efficacy of rCol7 replacement in human patients with RDEB
[0201] This study was performed to assess the efficacy of rCol7
replacement in treating
humans with RDEB. Adult Patients with Recessive Dystrophic Epidermolysis
Bullosa
(RDEB) are selected as described in Example 4. Twelve patients with a
diagnosis of RDEB
and a history of at least one chronic lesion were enrolled and divided into 4
dosing cohorts.
Patients received 3 doses of PTR-01 at doses ranging from 0.1 to 3.0 mg/kg. In
particular, the
four cohorts were dosed at 0.1 mg/kg (active drug), 0.3 mg/kg (active drug),
1.0 mg/kg
(active drug), and 3.0 mg/kg (active drug), respectively.
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[0202] Efficacy assessments were performed prior to first dose of
therapy, and repeatedly
during the treatment, and follow-up periods on Days 15, 29, 43, 57, 71, 85 and
127.
[0203] The pharmacokinetic parameter estimates including Cmax,
Tmax, AUC, clearance,
and t112 were measured. Skin samples were obtained and subject to IF staining
for Col7
staining at the dermal-epidermal junction (DEJ). Electron microscopy (EMS) was
also used
to assess anchoring fibrils in the skin biopsy. The duration of rhCol7 in
tissues was measured
in the skin biopsy.
[0204] Changes of skin blisters, skin lesion size, and wound
healing were assessed and
measurements of biomedical markers including albumin, iron/TIBC, hemoglobin,
and
hematocrit were also tested. Additionally, patient reported outcomes such itch
and pain scale,
overall life quality, and DEB activity, etc., were included as part of the
assessment,
[0205] The interim efficacy assessment data indicated a 200%
increase, on average, in C7
deposition at the dermal-epidermal junction (DEJ) by direct
imrnunofluorescence (DIE) was
seen at 1 mg/kg dose. A dose-dependent increase in C7 deposition at the DEJ
was shown
with the C7 levels at 3 mg/kg approaching those seen in asymptomatic
heterozygotes and
normal human skin.
[0206] A trend towards improved wound healing in patients was
observed. A dose-
dependent increase in this study with C. levels at 3 mg/kg approaching those
seen at the
minimum effective dose in animals. In addition, the increase in C7 DIF was
maintained for
about one month after discontinuation of dosing.
Example 6: Dosing frequency study in patients with RDEB
[0207] This Phase 2, Open-Label study deteimines the dose frequency
on incorporation of
rC7 in the skin and efficacy in patients with RDEB. The treatment plan to RDEB
patients
were divided into 3 parts including two dosing regimens (Parts 1 and 2,
alternately referred to
as "loading" and "maintenance" phases) and a 3-month observation phase (Part
3). In Part 1,
patients receive a dose of 3.0 mg/kg rCol7 every week for a total of 4 doses.
In Part 2,
following Part I, patients receive a dose of 3.0 mg/kg rCol7 every other week
for a total of 7
doses. An efficacy assessment is performed at the end of each dosing period.
During Part 3,
patients are evaluated at Months 1 and 3 after completion of dosing to access
the durability of
wound healing and other efficacy parameters. All the doses were administered
by intravenous
infusion. FIG. 4 schematically illustrates the study design.
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[0208] Dosing is scheduled as follows: For patients over 16 years of age
and older, PTR-
01 was administered at a dose of 3.0 mg/kg IV weekly for 4 doses, then every
other week for
7 doses; and for patients under 16 years of age, PTR-01 is administered at a
dose of 120
mg/m2IV weekly for 4 doses, then every other week for 7 doses.
[0209] Primary endpoints for this study included improvement in a majority
of target
lesions of at least 2 levels using a 7-point Global Impression of Change (GIC)
instrument, as
well as treatment-emergent adverse events (TEAEs), infusion-associated
reactions (IARs),
and immunogenicity. Secondary and exploratory endpoints included delivery of
PTR-01 to
skin; formation of new anchoring fibrils as measured by electron microscopy;
wound area of
target lesions by imaging; investigator G1C (1GIC) assessment; total body
wound surface
area; severity of pain and impact of pain on quality of life (modified PROMIS
subscales and
iscorEB); global impressions of severity and change (IGIS&C. PGIS&C); wound
care
burden; patient interviews and anecdotal reports; and markers of skin
fibrosis.
[0210] Table 8 summarizes details of patients enrolled in the study. Six
patients were
enrolled and five completed the study. Patients 202-001, 202-002, and 202-003
participated
in the Phase 1 study described in Example 5. The median patient age was 19.0
years.
Table 8. Details of study patients
201-001 202-001 202-002 202-003 203-001
203-002
Age 30 20 17 30 18 13
Gender Female Male Male Male Male
Male
Ethnicity White White White Non-White White
White
Heterozygous
Homozygous Heterozygous
c.7787deIG
Unknown
p.GLU2020ASN Heterozygous c.993C>G
Homozygous (exon 104);
p.G2013S
Mutation FSX183; c.4448G>A;
(p.Y311*);
R578X IVS26-3T
(exon 73);
p.GLU2020ASN c.8221C>T
c.7929+11_7929+
>g (mtron
n/a
FSX183 26DEL
26)
[0211] Table 9 summarizes wound response on Day 120 compared to baseline by
Wound-
Specific 7 Point Scale. In the table, m is the number of wounds that met the
response criteria;
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M is the total number of wounds; responders were patients with a >2-point
increase in the
wound-specific 7-point assessment scale in >50% of their wounds; and the total
wound
response is the total number of wounds (all patients) with a >2-point increase
in the wound-
specific 7-point assessment scale for all patients. The total number of
patients assessed was 5
rather than the 6 enrolled in the study as one patient discontinued after Day
36 due to lack of
efficacy.
Table 9. Wound response on Day 120 compared to baseline
Parameter Overall (N=6)
Number of patients with Day 120 assessment 5*
Responders ln (%)] 4 (66.7)
Non-responders [n (%)] 1 (16.7)
Response Rate (95% CI) 80.0 (28.4, 99.5)
Total wound response for all patients [m/M (%)1 18/26 (69.2)
*One patient discontinued after day 36 due to lack of efficacy.
[0212] FIG. 5 shows the comparison of Day 120 wound evaluations vs.
baseline. As
shown in Table 9 and FIG. 5, treatment with PTR-01 led to rapid, consistent,
and durable
wound healing. By Day 15, 15/26 wounds (57.7%) met the response criteria of >2-
point
increase in the wound-specific 7-point assessment scale, and at Day 120, 18/26
wounds
(69.2%) did. Based on these criteria, 4/6 patients (66.7%) were responders.
[0213] FIG. 6 shows the wound response by percent reduction in
wound surface area by
Canfield imaging. Wounds exhibited a rapid response to treatment with a
majority (80%)
reaching >50% closure by Day 68. At Day 120, the end of treatment, over 80% of
wounds
closed with >50% compared to baseline. Durability of treatment lasted one
month after the
last dose with treatment effects waning starting at Day 204.
[0214] FIG. 7 shows the wound closure observed in chronic and
recurrent wounds. PTR-
01 impacts wound closure in chronic wounds, which are a major source of
morbidity. This
analysis was based on 14 wounds characterized as "recurrent" and 8 wounds
characterized as
"chronic;" efficacy was similarly observed in small and large wounds. Of 26
wounds
analyzed in the study, 4 were labeled as "physician choice" per protocol and
therefore no
clinical wound history was provided and the wounds were omitted from the
analysis. Robust
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wound healing response was observed across different wound types: small and
large, chronic
and recurrent. The majority of wounds achieved healing of >50 and >75% on Day
120.
[0215] FIG. 8 shows example wound images demonstrating clear
reduction in wound
surface area post PTR-01 treatment across all types and sizes of wounds.
[0216] FIGs. 9A-9B show individual wound and median change from baseline in
wound
surface area. Using area under the curve (AUCi) analysis to examine wound size
over time
relative to baseline, there was a greater reduction at Day 43 in patients
receiving PTR-01 than
that observed in a historic Phase 1 PTR-01 study with patients receiving
placebo (53.6% vs.
75%).
[0217] FIGs. 10A-10B show improvements in pain, disease impact,
activities of daily
living, mood, and essential functions measured by iscorEB-P by patients in the
Phase 2 study.
Marked mean and median reductions from baseline to Day 204 were observed in
iscorEB
scores for these metrics.
[0218] FIG. 11 shows Investigator and Patient Global Impression of
Change (GIC) score
by patient and time point. At Days 22, 78, 120, and 148, both IGIC and PGIC
scores
improved, with good correlation between investigator and patient assessments.
[0219] FIG. 3 shows immunofluorescence data showing deposition of
C7 at the dermal-
epidermal junction (DEJ) following administration of PTR-01. The upper panels
show
deposition for patients previously treated in the Phase 1 study described in
Example 5, and
the lower panels show deposition for patients not treated in the prior study.
As shown in FIG.
3, deposition of C7 at the DEJ in patients who received PTR-01 at 0.3 mg/kg,
and 3 mg/kg
was dose dependent deposition. Rapid deposition of C7 at the DEJ was observed
during the
loading phase, achieving levels projected to confer a therapeutic effect (35%
of normal).
These levels were maintained throughout treatment and for one month following
treatment
completion. All patients exhibited continued deposition of C7 in the DEJ
compartment
ranging from one to three months following their last dose of PTR-01 (e.g.,
Day 148 and Day
204 timepoints). These data support the possibility of monthly, or perhaps
longer,
maintenance dosing.
[0220] FIG. 12 shows reduction in skin pro-fibrotic biomarker
staining with PTR-01
administration. Biomarkers of fibrosis decreased over the course of treatment
from an
elevated baseline, and remained reduced after treatment completion.
[0221] Overall, PTR-01 was well tolerated when given once per week
for 4 weeks and
then every other week for 14 weeks. Table 10 summarizes TEAEs observed in the
study.
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Twenty AEs were reported for 4 patients, all of which were resolved. No
deaths, severe
adverse events, or unexpected AEs were observed, and no AEs led to treatment
discontinuation. All AEs were mild or moderate except a single AE of anemia,
which was
considered not related to the study drug. One patient had infusion reactions
that responded to
supportive care and resolved within hours. Three patients had detectable low-
titer ADAs,
observed at least once during the study. These observations were not
associated with clinical
or laboratory manifestations. One patient had high-titer ADAs. This patient
had mild
infusion reactions and eventually withdrew from the study due to lack of
efficacy.
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Table 10. TEAEs observed in the Phase 2 study
TEAE tt of patients (events) Grades
Any TEAE 4 (20) I, II,
III
1ARs / AES1s 1 (10)
Infections 1 (2)
Palpitations 1 (1)
Dermatitis 1 (1)
Other vitals/lab abnormalities 2 (5) 1,11
Anemia 1 (1) III
[0222] In summary, weekly infusions of PTR-01 at 3.0 mg/kg per week
for 4 weeks
followed by every other week (q.o.w.) infusions for 14 weeks were well-
tolerated and
resulted in rapid and sustained improvements in measures of wound healing
including the
proportion of patients with at least a 2 point improvement in the majority of
wounds and the
proportion of total patient wounds with >50% reduction in surface area;
reduction in iscorEB
symptom scores; deposition of rC7 at the DEJ; and reduction of pro-fibrotic
biomarkers in the
skin. Investigator and patient global assessments of change were in agreement
and reflected
improvement in overall disease. The results of this study support further
investigation of
PTR-01 administration for the treatment of DEB.
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CA 03234797 2024-4- 11
